National Instruments NI 4050 User's Manual
Contents
1. Figure 2 2 Normal Mode Measurement Effects If you are measuring signals in the presence of large normal mode voltages consult Appendix A Specifications to calculate the additional error to your system Use the equation in Figure 2 2 to calculate the voltage error due to normal mode voltage Common Mode Rejection Common mode rejection CMR is the ability of the NI 4050 to reject signals that are common to both input terminals The ability is quantified in the common mode rejection ratio CMRR specification Theoretically the floating measurement circuitry of the NI 4050 should have an infinite CMRR Parasitic resistances and capacitances to earth ground limit the CMR of the NI 4050 This effect is most noticeable when measuring small signals in the presence of a large common mode voltage as shown in Figure 2 3 National Instruments Corporation 2 5 NI 4050 User Manual Chapter 2 NI 4050 Operation AC Voltage NI 4050 User Manual HI Measured Voltage Input Source V VQ gt Voltage m V O LO Common Voltage Ve CMRR V 20 S Verror gt Ve x 10 Vin Vs Verror Figure 2 3 Common Mode Measurement Effects Using the equation in Figure 2 3 you can calculate the voltage error due to the common mode voltage If you are measuring signals in the presence of large common mode voltages consult Appendix A Specifications to calculate the addit2. This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the instructions in this manual and the CE Mark Declaration of Conformity may cause interference to radio and television reception Classification requirements are the same for the Federal Communications Commission FCC and the Canadian Department of Communications DOC FOR HOME OR OFFICE USE Changes or modifications not expressly approved by National Instruments could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense Canadian Department of Communications This Class A digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe A r
3. 024 4 Q 0 027 4 Q 0 0020 0 40 Q 200 000 Q 0 006 0 4 Q 0 024 4 Q 0 027 4 Q 0 0020 0 40 Q Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linearity and noise Measurement MOdE ccccccseeseeeeeeees 2 wire Ohms T ste rrent saienitisi 100 pA for 200 Q 2 KQ 20 KQ ranges 1 uA for 2 MQ 200 kQ ranges 1 uA and 1 MQ in parallel for extended Ohms mode Diode Testing Accuracy of reading uV 24 Hour 90 Day 1 Year Temperature Coefficient Range 25 C 1 C 25 C 10 C 25 C 10 C of Reading C nV C 2V 0 006 60 uV 0 024 400 uV 0 027 400 uV 0 002 40 uV Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linearity and noise Test current National Instruments Corporation A 5 NI 4050 User Manual Appendix A Specifications General Specifications Physical Environment NI 4050 User Manual Sethin UME eaen aS Affected by source impedance and input signal changes Warm Up time ee eee cseceeceeeeeeeees 30 minutes for measurements accurate within specifications BUS BY Pe sik ied Se septs oaase PCMCIA slave Altitude arnoia triene Up to 2 000 m at higher altitudes the installation category must be derated Working voltage n se 250 V maximum between either input t
4. F filtering gain NI 4050 User Manual a parasitic phenomenon related to capacitors that can cause unexpectedly long settling times in circuits using capacitors with poor dielectric absorption specifications an analog input consisting of two terminals both of which are isolated from computer ground whose difference is measured digital multimeter differential nonlinearity a measure in LSB of the worst case deviation of code widths from their ideal value of 1 LSB a device that contains the necessary insulating structures to provide electric shock protection without the requirement of a safety ground connection software that controls a specific hardware instrument Effective Common Mode Rejection a measure of an instrument s ability to reject interference from a common mode signal This includes both the effects of normal mode rejection and common mode rejection electrically erasable programmable read only memory ROM that can be erased with an electrical signal and reprogrammed external trigger input signal farads a type of signal conditioning that allows you to filter unwanted signals from the signal you are trying to measure the factor by which a signal is amplified sometimes expressed in decibels G 4 www ni com H harmonics half power bandwidth hardware ex IEC IEEE in inductance input bias current input impedance Installation Category Overvoltage Category instrument driver
5. OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Compliance FCC Canada Radio Frequency Interference Compliance Determining FCC Class The Federal Communication
6. interrupt interrupt level T O National Instruments Corporation G 5 Glossary multiples of the fundamental frequency of a signal the frequency range over which a circuit maintains a level of at least 3 dB with respect to the maximum level the physical components of a computer system such as the circuit boards plug in boards chassis enclosures peripherals cables and so on hertz per second as in cycles per second or samples per second excitation current International Electrotechnical Commission Institute of Electrical and Electronics Engineers inches the relationship of induced voltage to current the current that flows into the inputs of a circuit the measured resistance and capacitance between the input terminals of a circuit classification system for expected transients on electrical supply installations a set of high level software functions that controls a specific plug in DAQ board Instrument drivers are available in several forms ranging from a function callable language to a virtual instrument VI in LabVIEW a computer signal indicating that the CPU should suspend its current task to service a designated activity the relative priority at which a device can interrupt input output the transfer of data to from a computer system involving communications channels operator interface devices and or data acquisition and control interfaces NI 4050 User Manual Glossary ISA isolation is
7. the AC voltages are large compared to the DC voltages or if the peak value AC DC of the measured voltage is outside the overrange limits the NI 4050 may exhibit additional errors To minimize these errors keep the NI 4050 away from strong AC magnetic sources and minimize the area of the loop formed by the test leads Choosing the 5 1 2 digit resolution will also help minimize noise from AC sources If the peak value of the measured voltage is likely to exceed the selected input range select the next highest input range Normal Mode Rejection Normal mode rejection NMR is the ability of the NI 4050 to reject a normally differentially applied signal The ability is quantified in the normal mode rejection ratio NMRR specification which indicates the capability of the NI 4050 to reject 50 or 60 Hz and is valid only at the specified frequency and useful only when taking DC measurements The NMRR is specified at the powerline frequency because this is typically where most measurement noise occurs Figure 2 2 shows a 60 Hz signal connected differentially to the NI 4050 in DC Volts mode V is the voltage that will be measured after the signal is rejected NMR is very useful when trying to measure DC voltages in the presence of large powerline interference 2 4 www ni com Chapter 2 NI 4050 Operation HI eaa Input Source Ea VQ gt Voltage m V at 60 Hz tL CO LO AMR 20 Vm Vz x 10
8. this document must be used in an Installation Category I environment per IEC 664 This category requires local level supply mains connected installation The NI 4050 must be used in a UL listed laptop or personal computer To prevent safety hazards the maximum voltage between either of the inputs and the ground of the computer should never exceed 250 VDC or 250 Vims Do not operate damaged equipment The safety protection features built into this instrument can become impaired if the instrument becomes damaged in any way If the instrument is damaged do not use it until service trained personnel can check its safety If necessary return the instrument to National Instruments for service and repair to ensure that its safety is not compromised Do not operate this instrument in a manner that contradicts the information specified in this document Misuse of this instrument could result in a shock hazard Do not substitute parts or modify equipment Because of the danger of introducing additional hazards do not install unauthorized parts or modify the instrument Return the instrument to National Instruments for service and repair to ensure that its safety is not compromised Connections that exceed any of the maximum signal ratings on the NI 4050 can create a shock or fire hazard or can damage any or all of the devices connected to the NI 4050 National Instruments is not liable for any damages or injuries resulting from incorrect signal conn
9. volts volts alternating current volts direct current voltage error virtual instrument 1 a combination of hardware and or software elements typically used with a PC that has the functionality of a classic stand alone instrument 2 a LabVIEW software module VI which consists of a front panel user interface and a block diagram program voltmeter complete signal volts root mean square value the voltage that is created across the device under test when excited by a current the shape the magnitude of a signal creates over time the highest voltage that should be applied to a product in normal use normally well under the breakdown voltage for safety margin NI 4050 User Manual Index A AC current specifications A 4 AC voltage measurement 2 6 to 2 8 AC offset voltage 2 7 frequency response 2 7 to 2 8 input ranges 2 7 using VirtualBench DMM Soft Front panel 1 5 to 1 6 AC voltage specifications A 3 C cables and probes 1 1 to 1 2 installing 1 1 to 1 2 overview l 1 common mode rejection 2 6 to 2 7 continuity measurements 2 9 conventions used in manual vi current measurement 1 8 D DC current specifications A 2 DC voltage measurement 2 2 to 2 6 common mode rejection 2 6 to 2 7 effective common mode rejection 2 6 input impedance 2 3 input ranges 2 3 noise rejection 2 4 to 2 6 normal mode rejection 2 4 to 2 5 thermal EMF 2 4 using VirtualBench DMM Soft Front panel 1 5 to 1 6 DC
10. 2 Figure 1 2 NI DMM Soft Front Panel oo ceseeseeeeceeceeeeseecaeceeeeeneeseees 1 3 Figure 1 3 Di pits of Precast ss ecssvepsesassseeveess tE A eE En ea pipes EEE KAE ES ESEESE R T 1 5 Figure 1 4 Connecting Probes for Voltage Measurement 0 eee ee eeeeee eee 1 6 Figure 1 5 Connections for Resistance Measurement 0 cece cee cereeeeeeeees 1 7 Figure 1 6 Connecting Signals for Diode Test eee eceeeeeeeeeereesseceensees 1 7 Figure 1 7 Connections for Current Measurement cee eeceeeeeeeceeeeeeseeeeees 1 8 Figure 1 8 Connecting Signals for RTDs and Thermistors 00 00 eeees 1 9 Figure 2 1 Effect of Input Impedance on Signal Measurements eee 2 3 Figure 2 2 Normal Mode Measurement Effects eee eeeeeeeeeseeeee cee eneeeeeeeees 2 5 Figure 2 3 Common Mode Measurement Effects 0 eee eee eseeeee ce eeeeeeeeeees 2 6 Figure 2 4 Circuit for 2 Wire Resistance Measurements ce eeeeeeeeeeeeeeees 2 8 Figure 2 5 Circuit for Diode Measurements eee eeeeeeeeeeeeeeeeeeteeeeeneeerees 2 9 NI 4050 User Manual viii www ni com Taking Measurements with the NI 4050 Thank you for buying a National Instruments 4050 digital multimeter card A system based on the NI 4050 offers the flexibility performance and size that makes it ideal for service repair and manufacturing as well as for use in industrial and laboratory environments The NI 4050 used in conjunction with your computer is a versati
11. 3 1 2 digit setting gives you the least resolution and fastest reading rate Measurement mode and range affect the reading rate by requiring different conversion times to obtain a given resolution for the different modes and ranges When measuring ground referenced signals connect the ground referenced side of your signal to the IN HI terminal for best performance Voltage Measurements DC Voltage NI 4050 User Manual Your NI 4050 multimeter uses a high resolution delta sigma A D converter ADC to sample signals and convert them into a digital form The ADC is preceded by a series of gain and attenuation circuitry that allow both small and large signals to be measured using the same converter The NI 4050 uses a digital filter which heavily rejects powerline frequencies 50 60 Hz and their harmonics as well as high frequency noise 2 2 www ni com Chapter 2 NI 4050 Operation Input Ranges The NI 4050 has five input ranges available for measuring DC voltages These ranges are 20 mV 200 mV 2 0 V 25V and 250 V Each range has a 10 overrange except for the 250 V range The 250 V and 25 V input ranges have a 1 MQ input impedance the 2 V 200 mV and 20 mV ranges have an input impedance greater than 1 GQ Take these values into consideration when measuring high impedance sources When the NI 4050 is powered off the 250 V and 25 V input range have a 1 MQ input impedance and the 2 V 200 mV and 20 mV ranges have an inpu
12. 5 C 10 C of Reading C mV C 250 000 V 0 6 500 mV 0 62 680 mV 0 62 680 mV 0 007 20 mV 25 0000 V 0 3 30 mV 0 32 210 mV 0 32 210 mV 0 007 20 mV 2 00000 V 0 4 3 mV 0 42 21 mV 0 42 21 mV 0 019 2 mV 200 000 mV 0 3 0 22 mV 0 32 1 20 mV 0 32 1 20 mV 0 007 0 110 mV 20 0000 mV 0 4 100 uV 0 42 170 uV 0 42 170 uV 0 019 12 uV Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linerarity and noise applies for sine waves gt 10 of input range Accuracy may be affected by source impedance cable capacitances dielectric absorption or slew rate Noise Rejection AC CMRR DC to 60 HZ eee gt 80 dB with a 1 KQ imbalance in LO lead Input Characteristics Input resistance eeeceeeeceeeeeneceeeeeeees 1 MQ all ranges Bandwidth 0 cceeceeesseeessceeesteeeseeeees 20 Hz 25 kHz Additional AC Errors Frequency dependent errors Input Frequency Additional Error of Reading 20 50 Hz 2 5 50 100 Hz 1 100 Hz 5 kHz 0 5 10 kHz 1 10 25 kHz 2 5 A 3 NI 4050 User Manual National Instruments Corporation Appendix A Specifications AC Current Accuracy of reading mA AC current measurements require the use of the CSM current shunt module 24 Hour 90 Da
13. Computer Based Instruments NI 4050 User Manual Digital Multimeter Card for PCMCIA Qr NATIONAL March 2000 Edition gt INSTRUMENTS Part Number 321427C 01 Worldwide Technical Support and Product Information www ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 794 0100 Worldwide Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 China 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico D F 5 280 7625 Mexico Monterrey 8 357 7695 Netherlands 0348 433466 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 0 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 For further support information see the Technical Support Resources appendix To comment on the documentation send e mail to techpubs ni com Copyright 1999 2000 National Instruments Corporation All rights reserved Important Information Warranty The NI 4050 is warranted against defects in materials and workmanship for a period of one y
14. PXI range error reading error reading rate resolution rms ROM Reense National Instruments Corporation G 7 Glossary Peripheral Component Interconnect a high performance expansion bus architecture originally developed by Intel to replace ISA and EISA it is achieving widespread acceptance as a standard for PCs and workstations and offers a theoretical maximum transfer rate of 132 Mbytes s the absolute maximum or minimum amplitude of a signal AC DC PCI eXtensions for Instrumentation PXI is an open specification that builds off the CompactPCI specification by adding instrumentation specific features resistor random access memory an error in accuracy that is determined by the input range that is selected The range error is independent of the value of the signal being measured an error in accuracy that is determined by the input range as well as the value being measured the rate at which a new measurement is taken In addition to the measurement speed the selection of the reading rate affects the filtering and thus the noise level of measurements the smallest signal increment that can be detected by a measurement system Resolution can be expressed in bits or in digits The number of bits in a system is roughly equal to 3 3 times the number of digits root mean square a measure of signal amplitude the square root of the average value of the square of the instantaneous signal amplitude read on
15. a European Union Compliance to EEC Directives Readers in the EU EEC EEA must refer to the Manufacturer s Declaration of Conformity DoC for information pertaining to the CE Mark compliance scheme The Manufacturer includes a DoC for most every hardware product except for those bought for OEMs if also available from an original manufacturer that also markets in the EU or where compliance is not required as for electrically benign apparatus or cables Certain exemptions may apply in the USA see FCC Rules 15 103 Exempted devices and 15 105 c Also available in sections of CFR 47 The CE Mark Declaration of Conformity will contain important supplementary information and instructions for the user or installer Conventions bold italic monospace The following conventions are used in this manual The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash Bold text denotes items that you must select or click on in the software such as menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables
16. ader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident acti
17. asure the forward voltage of a diode make sure that the diode is not connected to any other circuits The NI 4050 biases the diode with a current of 100 uA and measures the resulting voltage drop Diode measurements are made with a fixed range of 2 0 V 100 uA Ty EMA XZ Diode LO Figure 1 6 Connecting Signals for Diode Test National Instruments Corporation 1 7 NI 4050 User Manual Chapter 1 Taking Measurements with the NI 4050 gt Volts Ena Measure Current NI 4050 User Manual 2 Select diode mode 3 Select the range for your measurement Only the 2 V range is available for diode measurement The value indicator will indicate the voltage drop measured If the display indicates 2 200 VDC the diode is either reverse biased or defective See the Diode Measurements section of Chapter 2 NI 4050 Operation for more information on diode measurements You can use the NI 4050 to measure current with an optional National Instruments CSM series current shunt module These accessories are connected between the NI 4050 cable and the test probes as shown in Figure 1 7 ood 4 Current Source Current Shunt Accessory Figure 1 7 Connections for Current Measurement Current shunt accessories contain a precision resistor that converts the current through the shunt into a voltage that the NI 4050 can measure in voltage mode Whi
18. bes connect to the NI 4050 accessory cable via shrouded banana jacks The shrouds around the banana jacks prevent you from contacting potentially hazardous voltages connected to the test probes You can also connect the cable to standard unshrouded banana jack probes or accessories however use unshrouded probes or accessories only when the voltages are less than 30 Vim Or 42 Vok to pk UN Caution To prevent possible safety hazards the maximum voltage between either of the inputs and the ground of the computer should never exceed 250 VDC or 250 V ms NI 4050 User Manual 1 2 www ni com Chapter 1 Taking Measurements with the NI 4050 Introduction to the VirtualBench DMM Soft Front Panel CJ VirtualBench DMM The following sections explain how to make connections to your NI 4050 and take simple measurements using the VirtualBench DMM as shown in Figure 1 2 To launch the soft front panel select Start Programs National Instruments DMM Soft Front Panel o File Edit Window Utility Help voc 250 BG 2 200m 20m Awo m jumjum Run Singe Null wu mB Log a a as Jame 76 ee Figure 1 2 NI DMM Soft Front Panel The following text describes the options available on the soft front panel Refer to Help Online Reference located on the soft front panel for information on front panel menus The range selector determines the range of measurements VirtualBench DMM makes The range differs for each measur
19. current Input resistance National Instruments Corporation A 1 vides ESA 1 nA max EEE EEE gt 1 GQ 2 V 200 mV 20 mV ranges 1 MQ 250 V 25 V NI 4050 User Manual Appendix A Specifications DC Current Accuracy of reading WA DC current measurements require the use of the CSM current shunt modules 24 Hour 90 Day 1 Year Temperature Coefficient Range 25 C 1 C 25 C 10 C 25 C 10 C of Reading C pA C 200 000 mA 0 1 27 uA 0 14 250 pA 0 15 250 uA 0 0035 25 uA 20 0000 mA 0 1 27 uA 0 14 250 uA 0 15 250 uA 0 0035 25 uA 10 0000 A 0 02 4 mA 0 035 26 mA 0 035 26 mA 0 007 2 5 mA Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linerarity and noise Requires 200 mA shunt CSM 200mA Requires 10 A shunt CSM 10A Input Characteristics 200 mA shunt Input protection oes Fuse F1 500 mA 250 V fast fusing Shunt resistor eee eee eeeeeeeee 1Q Burden voltage eee eee lt 400 mV at 200 mA 10 A shunt Input protection oes Fuse F1 12 5 A 250 V fast fusing Shunt resistor oo eee eee eeeeeeeeee 10 mQ Burden voltage eee eee lt 300 mV at 10 A NI 4050 User Manual A 2 www ni com Appendix A Specifications AC Voltage Accuracy of reading mV 24 Hour 90 Day 1 Year Temperature Coefficient Range 25 C 41 C 25 C 10 C 2
20. d 2 V input ranges have a 0 068 uF capacitor followed by a 1 MQ input impedance The 200 mV and 20 mV ranges have a 0 068 uF capacitor followed by an approximate 100 kQ input impedance The NI 4050 can measure AC voltages to its specified accuracy as long as the voltage is at least 10 and no more than 100 of the selected input range The DC component in any of these ranges can be as high as 250 VDC Each range except for the 250 V range has a 10 overrange The AC voltage measurement accuracy depends on many factors including the signal amplitude frequency and waveform shape Measurement Considerations AC Offset Voltage The AC measurements of the NI 4050 are specified over the range of 10 to 100 of the full scale input range Below 10 of the input range errors due to the AC voltage offset become significant This offset unlike DC voltage offsets cannot simply be subtracted from the readings or zeroed out because the offset gets converted in the RMS conversion To minimize the errors due to the AC offset voltage choose an input range that keeps the measured voltage between 10 and 100 of full scale Frequency Response The accuracy of the NI 4050 s AC voltage measurements is a function of the input signal frequency Your NI 4050 is calibrated at the factory using a 1 kHz sine wave Your frequency dependent error will be minimal around this frequency The error will then increase as you approach the upper and lower bandwi
21. dicator displays the voltage measured Measure 2 Wire Resistance Use the following procedure to measure 2 wire resistance using the soft front panel 1 Connect the test probes to a resistor as shown in Figure 1 5 To accurately measure the value of a resistor make sure the resistor is not connected to any other circuits Erroneous or misleading readings may result if the resistor you are measuring is connected to external circuits that supply voltages or currents or to external circuits that change the effective resistance of that resistor NI 4050 User Manual 1 6 www ni com Chapter 1 Taking Measurements with the NI 4050 Resistor Figure 1 5 Connections for Resistance Measurement A 2 Select 2 wire resistance mode Ohms 200M 2M zo0k 2k ak EN 3 Select the range for your measurement 200 Q 2 KQ 20 kQ 200 kQ wfo lafo o 2 MQ 200 MQ or autorange The value indicator indicates the resistance measured See the 2 Wire Resistance Measurements section of Chapter 2 NI 4050 Operation for more information on 2 wire resistance measurements Measuring the Voltage Drop Across a Diode The NI 4050 can excite a device under test and read the resulting voltage drop Diode mode is useful for testing diodes Use the following procedure to measure the forward drop across a diode Voltage up to 2 V can be measured in this mode 1 Connect the test probes to a diode as shown in Figure 1 6 To accurately me
22. dth limits This additional error is added to the accuracy errors in computing the absolute error National Instruments Corporation 2 7 NI 4050 User Manual Chapter 2 NI 4050 Operation These additional errors are shown in Appendix A Specifications While the NI 4050 is characterized and specified over the 20 Hz to 25 kHz frequency range measurements outside of this range can still be made with decreased accuracy Resistance Measurements 2 Wire Resistance NI 4050 User Manual Measurements The NI 4050 measures 2 wire resistance by passing a current through the device under test and reading the resulting voltage drop through the same connections as illustrated in Figure 2 4 The resistance value is then computed using Ohm s Law R V I To accurately measure the value of a resistor make sure the resistor is not connected to any other circuits Erroneous or misleading readings can result if the resistor you are measuring is connected to external circuits that supply voltages or currents or to external circuits that change the effective resistance of that resistor Ho O A Input Vsense Cy C1 lex VQ Runknown O LO lx Vse Runknown soree ex l x 100 WA 200 Q 2 KQ 20 KQ ranges 1 uA 200 kQ 2 MQ 200 MQ ranges Figure 2 4 Circuit for 2 Wire Resistance Measurements Input Ranges The NI 4050 has five basic input ranges for 2 wire resistance as we
23. ear from the date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The re
24. ections Clean the instrument and accessories by brushing off light dust with a soft nonmetallic brush Remove other contaminants with a stiff nonmetallic brush The unit must be completely dry and free from contaminants before returning to service National Instruments Corporation 2 1 NI 4050 User Manual Chapter 2 NI 4050 Operation Measurement Fundamentals Warm Up The required warm up time for the NI 4050 is 30 minutes This warm up time is important because measurements made with the NI 4050 multimeter can change with temperature This change is called a thermal drift and affects your accuracy To minimize the effects of thermal drift and ensure the specified accuracies take all measurements after the NI 4050 has had a chance to fully warm up Depending on your environment the NI 4050 can operate significantly above ambient temperature Therefore measurements made immediately after powering up the system can differ significantly from measurements made after the system has fully warmed up The NI 4050 temperature specifications are listed in the Accuracy sections in Appendix A Specifications Selecting the Resolution Grounding The resolution on the NI 4050 multimeter is programmable You can select from three different resolutions 5 1 2 digits 4 1 2 digits or 3 1 2 digits These settings allow you to trade off speed for resolution The 5 1 2 digit setting has the highest resolution and slowest reading rate while the
25. elp WWE w Wur 1Um Auto e e oe Function Run Single Null wis mB Loc v ve as av a 2 Figure 1 3 Digits of Precision Use the Soft Front Panel The following sections describe procedures for measuring DC and AC voltage resistance diode and temperature using the soft front panel Measure DC and AC Voltage Use the following procedure to measure DC and AC voltage using the soft front panel 1 Connect the test probes to voltage signals as shown in Figure 1 4 For DC voltages the HI red terminal is the positive terminal and the LO black terminal is negative For AC voltages positive and negative terms are irrelevant National Instruments Corporation 1 5 NI 4050 User Manual Chapter 1 Taking Measurements with the NI 4050 The NI 4050 is protected against damage from voltages within 250 VDC or 250 Vms in all ranges You should never apply voltages above these levels to the inputs all J 250 V DC Voltage 250V AC Voltage Emax Source T Source LO jia i0 ae Figure 1 4 Connecting Probes for Voltage Measurement 2 Select the mode you will measure ve DC Volts va e AC Volts S a E Eti ak a 3 Select the range for your measurement or autoranging Auto m a e DC Volts 20 mV 200 mV 2 V 25 V and 250 V e AC Volts 20 mV ms 200 MVims 2 Vims 25 Vims and 250 Vis The value in
26. ement mode If the measurement exceeds the range t OVER or OVER appears in the measurement display Auto selects the range that best matches the input signal The value indicator displays the value measured by your NI 4060 The value shown is an example only The unit indicator displays the measurement units of the value you are measuring The units are expressed as VAC VDC mVAC mVDC Q kQ MQ mA AC or mA DC The indicator also displays the digits of resolution By clicking on the indicator you can change the DMM s resolution National Instruments Corporation 1 3 NI 4050 User Manual Chapter 1 Taking Measurements with the NI 4050 Function ve ve az ar a 2 BE Fle EEEEE ale JH c El E dBm NI 4050 User Manual The Function selector allows you select a measurement mode Select Edit Settings and click on the tabs for Current and Resistance or Temperature to control the data type acquired by VirtualBench DMM DC volts measures the DC component of a voltage signal AC volts measures the AC component of a voltage signal DC current measures the DC component of a current source AC current measures the AC component of a current source 2 wire measures resistance using the 2 wire method 4 wire measures resistance using the 4 wire method Diode measures the voltage drop across a diode The maximum voltage VirtualBench DMM measures is 2 V Temperature measures temperature The run button star
27. emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts Contents Chapter 1 Taking Measurements with the NI 4050 Cable and Prob sjeeiccsescedtecesdosssoccedeess daccdiccstesdouveetevedeedt cove e an aae RRR 1 1 Introduction to the VirtualBench DMM Soft Front Panel ccccccccccccsessceeeceeenees 1 3 Usesthe S oft Front Paneline nenen a E ES 1 5 Measure DC and AC Voltage ssseseseeeeeseeeseeesserssresssreresrersresrrrenrerrnseeresrere 1 5 Measure 2 Wire Resistance ccccsssccececssssceececessececeeceessceseeceesssesecesensaeseeees 1 6 Measure the Voltage Drop Across a Diode eee eeceeeeceseeessecencecneeeeneceeneenes 1 7 Measure Current a a A S E ventencseeieeence ees 1 8 Measure Temperature minen ann e a a e 1 9 Chapter 2 NI 4050 Operation Safety INStruCtlOns wte ernes en r E orou E E T EEE E HEER SEn 2 1 Measurement Fundamentals ssccesseceseecsseesececereessecesceceaecenceceeeecseceeaeeneeesaeceaeeses 2 2 Wam U Derat ea ceive durant an
28. erminal and earth ground Power requirement eseeeseseseereerereeeee 5 VDC 45 mA in operational mode Saletyise a A S Designed in accordance with IEC 1010 1 and UL 3111 for electrical measuring and testing equipment Installation Category II Pollution Degree 2 Double Insulated Indoor use UL 3111 listed Dimensions s sseseeeeeseeeesererrerserersrreerereee Type II PC Card Operating temperature ee 0 to 55 C Storage temperature 0 eee eee eee 20 to 70 C Relative humidity oe eee eee 10 to 90 noncondensing A 6 www ni com Technical Support Resources This appendix describes the comprehensive resources available to you in the Technical Support section of the National Instruments Web site and provides technical support telephone numbers for you to use if you have trouble connecting to our Web site or if you do not have internet access NI Web Support To provide you with immediate answers and solutions 24 hours a day 365 days a year National Instruments maintains extensive online technical support resources They are available to you at no cost are updated daily and can be found in the Technical Support section of our Web site at www ni com support Online Problem Solving and Diagnostic Resources e KnowledgeBase A searchable database containing thousands of frequently asked questions FAQs and their corresponding answers or solutions including special sections devoted to our newest produc
29. especte toutes les exigences du R glement sur le mat riel brouilleur du Canada Class B Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver e Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe B respecte toutes les exigences du R glement sur le mat riel brouilleur du Canad
30. ional error to your system Effective Common Mode Rejection Effective common mode rejection is the sum of the CMRR and the NMRR at a given frequency It is the effective rejection on a given noise signal that is applied to both input leads as it gets rejected first by the CMR capability of the instrument then again by its NMR capability This specification is most useful at the powerline frequency where most of the noise resides and is only valid for DC measurements In the AC voltage ranges the NI 4050 measures the AC coupled RMS value of a signal The RMS value of a signal is a fundamental measurement of the magnitude of an AC signal The RMS value of an AC signal can be defined mathematically as the square root of the average of the square of the signal In practical terms the RMS value of an AC signal is the DC value required to produce an equivalent amount of heat in the same resistive load The NI 4050 first AC couples the measured signal to remove any DC 2 6 www ni com Chapter 2 NI 4050 Operation components and then measures the RMS value of the AC component This method lets you measure a small AC signal in the presence of a large DC offset Input Ranges The NI 4050 has five input ranges available for measuring AC voltages These ranges are 20 mV 200 MV ms 2 0 Vins 25 Vims and 250 Vins The impedance in each of these ranges is a 0 068 uF capacitor followed by 1 MQ When the NI 4050 is powered off the 250 V 25 V an
31. le cost effective platform for high resolution measurements For the most current versions of manuals and example programs visit www ni com instruments for free downloads Detailed specifications for the NI 4050 are in Appendix A Specifications 3 Note Before using any measurement equipment it is important that you thoroughly understand the safety instructions for that product The beginning of Chapter 2 NI 4050 Operation covers the safety guidelines for your NI 4050 Cable and Probes The NI 4050 instrument kit contains the NI 4050 accessory cable that connects the NI 4050 to a pair of test probes with shrouded banana plugs which are also included in the kit Both the NI 4050 accessory cable and the test probes meet international safety requirements including UL 3111 and IEC 1010 1 for the full ranges of applications supported by the NI 4050 Before using any probes or accessories not supplied by National Instruments ensure that they meet applicable safety requirements for the signal levels you may encounter To use the NI 4050 accessory cable and probes with the NI 4050 first connect the cable to the card as shown in Figure 1 1 The accessory cable connector is polarized so that it cannot be plugged in incorrectly National Instruments Corporation 1 1 NI 4050 User Manual Chapter 1 Taking Measurements with the NI 4050 Portable Computer Figure 1 1 Installing the NI 4050 and Cables The test pro
32. le the soft front panel cannot measure current directly with the NI 4050 you can calculate the value of the current flowing through the shunt by dividing the voltage measured by the value of the precision resistor 1 8 www ni com Chapter 1 Taking Measurements with the NI 4050 Measure Temperature You can measure temperature using common temperature transducers such as resistive temperature devices RTD and thermistors You can measure transducers in the 2 wire resistance mode as shown in Figure 1 8 Although the soft front panel does not support temperature measurements you can convert and scale the transducer value to temperature programmatically through software Sy Note The NI 4050 for PCMCIA does not support 4 wire resistance measurements To avoid measurement errors due to resistance offset before doing resistance measurements measure the resistance to your loads m HI ENA i Resistor LO Figure 1 8 Connecting Signals for RTDs and Thermistors National Instruments Corporation 1 9 NI 4050 User Manual NI 4050 Operation This chapter contains safety instructions measurement fundamentals and concerns and scanning information Safety Instructions UN Cautions To avoid personal injury or damage to electronic equipment observe the following Do not operate this instrument in an explosive atmosphere or where there may be flammable gases or fumes Equipment described in
33. ll as an extended range The basic ranges are 200 Q 2 0 kQ 20 kQ 200 kQ and 2 MQ With the extended range measurements up to at least 200 MQ are possible www ni com Chapter 2 NI 4050 Operation In the extended ohms range the NI 4050 adds a 1 MQ resistor in parallel with the test resistor and then calculates the value of the resistor being tested The test current for the 200 Q 2 0 KQ and 20 KQ ranges is 100 pA The test current for the 200 KQ 2 MQ and 200 MQ ranges is 1 pA Continuity Measurements Many traditional multimeters can take continuity measurements which test for the presence or absence of continuity between the two test probes These measurements are simply resistance measurements where the resistance between the two probes is measured and compared to a set value You can perform continuity measurements on a circuit by setting the NI 4050 to the 200 Q range and comparing the measured value to some low resistance value typically 10 Q If the measured value is less than 10 Q there is continuity between the test probes Diode Measurements To properly measure the forward voltage of a diode make sure that the diode is not connected to any other circuits The NI 4050 biases the diode with a current of 100 WA and measures the resulting voltage drop as illustrated in Figure 2 5 Diode measurements are made with a fixed range of 2 0 V Note Different multimeters use different currents to excite the diode This ma
34. ly memory the sense resistor The voltage across this resistor is measured and converted to a current NI 4050 User Manual Glossary sense settling time S s system noise T temperature coefficient thermal drift thermoelectric potentials thermal EMFs transfer rate UL NI 4050 User Manual seconds samples in four wire resistance the sense measures the voltage across the resistor being excited by the excitation current the amount of time required for a voltage to reach its final value within specified limits samples per second used to express the rate at which an instrument samples an analog signal a measure of the amount of noise seen by an analog circuit or an ADC when the analog inputs are grounded the percentage that a measurement will vary according to temperature See also thermal drift measurements that change as the temperature varies See thermal EMFs thermal electromotive forces voltages generated at the junctions of dissimilar metals that are functions of temperature Also called thermoelectric potentials the rate measured in bytes s at which data is moved from source to destination after software initialization and set up operations the maximum rate at which the hardware can operate Underwriters Laboratory G 8 www ni com V v VAC VDC Veror VI VMC Vai sense W waveform shape working voltage National Instruments Corporation G 9 Glossary
35. ncies the period of time over which a measurement is averaged also called the number of powerline cycles to reduce in magnitude technique of internally shorting the internal circuit while disconnecting the measurement to compensate for temperature effects bit one binary digit either 0 or 1 byte eight related bits of data an eight bit binary number Also used to denote the amount of memory required to store one byte of data the group of conductors that interconnect individual circuitry in a computer Typically a bus is the expansion vehicle to which I O or other devices are connected Examples of PC buses are the PCI and ISA bus the voltage drop across the input section of the current mode Celsius common mode rejection ratio a measure of an instrument s ability to reject interference from a common mode signal usually expressed in decibels dB G 2 www ni com CompactPCI conversion device conversion time coupling CPU crest factor CSM D DAQ dB DC default setting device National Instruments Corporation Glossary refers to the core specification defined by the PCI Industrial Computer Manufacturer s Group PICMG device that transforms a signal from one form to another For example analog to digital converters ADCs for analog input digital to analog converters DACs for analog output digital input or output ports and counter timers are conversion devices the time req
36. olation voltage MB NI DAQ NMRR noise 0 Ohm s Law overrange NI 4050 User Manual industry standard architecture a type of signal conditioning in which you isolate the transducer signals from the computer for safety purposes This protects you and your computer from large voltage spikes and makes sure the measurements from the DAQ device are not affected by differences in ground potentials the voltage that an isolated circuit can normally withstand usually specified from input to input and or from any input to the amplifier output or to the computer bus meters megabytes of memory National Instruments driver software for DAQ hardware normal mode rejection ratio a measure of an instrument s ability to reject a signal applied directly to the differential inputs of the instrument an undesirable electrical signal Noise comes from external sources such as the AC power line motors generators transformers fluorescent lights soldering irons CRT displays computers electrical storms welders radio transmitters and internal sources such as semiconductors resistors and capacitors Noise corrupts signals you are trying to send or receive R V I the relationship of voltage to current in a resistance a segment of the input range of an instrument outside of the normal measuring range Measurements can still be made usually with a degradation in specifications G 6 www ni com PCI peak value
37. ons of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks CVI ComponentWorks LabVIEW National Instruments ni com NI DAQ SCXI and VirtualBench are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS
38. port B 1 to B 2 NI 4050 See also measurement specifications cables and probes 1 1 to 1 2 features 1 1 NI 4050 User Manual l 2 fundamentals of measurement grounding 2 2 selecting resolution 2 2 warm up time 2 2 noise rejection AC voltage specifications A 3 DC voltage measurement 2 4 to 2 6 common mode rejection 2 6 to 2 7 effective common mode rejection 2 6 normal mode rejection 2 4 to 2 5 DC voltage specifications A 1 normal mode rejection 2 4 to 2 5 0 online problem solving and diagnostic resources B 1 operation of NI 4050 See measurement P physical specifications A 6 probes and cables 1 1 to 1 2 installing 1 1 to 1 2 overview 1 1 problem solving and diagnostic resources online B 1 R resistance measurement 2 8 to 2 9 continuity 2 9 two wire 2 8 to 2 9 circuit figure 2 8 input ranges 2 8 to 2 9 using VirtualBench DMM Soft Front panel 1 6 to 1 7 resistance specifications A 5 resolution selection 2 2 National Instruments Corporation S safety instructions 2 1 soft front panel See VirtualBench DMM Soft Front panel software related resources B 2 specifications A 1 to A 6 AC current A 4 AC voltage A 3 DC current A 2 DC voltage A 1 diode testing A 5 environment A 6 general A 6 physical A 6 resistance A 5 T technical support resources B 1 to B 2 temperature measurements using VirtualBench DMM Soft Front panel 1 9 thermal EMF DC voltage measuremen
39. ramming environments You can use them to complement the example programs that are already included with National Instruments products e Software Library A library with updates and patches to application software links to the latest versions of driver software for National Instruments hardware products and utility routines Worldwide Support NI 4050 User Manual National Instruments has offices located around the globe Many branch offices maintain a Web site to provide information on local services You can access these Web sites from www ni com worldwide If you have trouble connecting to our Web site please contact your local National Instruments office or the source from which you purchased your National Instruments product s to obtain support For telephone support in the United States dial 512 795 8248 For telephone support outside the United States contact your local branch office Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 011 284 5011 Canada Calgary 403 274 9391 Canada Ontario 905 785 0085 Canada Qu bec 514 694 8521 China 0755 3904939 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 30 1 42 96 427 Hong Kong 2645 3186 India 91805275406 Israel 03 6120092 Italy 02 413091 Japan 03 5472 2970 Korea 02 596 7456 Mexico D F 5 280 7625 Mexico Monterrey 8 357 7695 Netherlands 0348 433466 New Zealand 09 914 0488 No
40. rway 32 27 73 00 Poland 0 22 528 94 06 Portugal 351 1 726 9011 Singapore 2265886 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 B 2 www ni com Glossary Prefix Meanings Value p pico 10 2 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 Numbers Symbols percent positive of or plus negative of or minus per degree plus or minus Q ohm A amperes AC alternating current AC coupled the passing of a signal through a filter network that removes the DC component of the signal A D analog to digital National Instruments Corporation G 1 NI 4050 User Manual Glossary ADC ADC resolution ADE amplification amplitude flatness aperture time attenuate autozero bus burden voltage C C CMRR NI 4050 User Manual analog to digital converter an electronic device often an integrated circuit that converts an analog voltage to a digital number the resolution of the ADC which is measured in bits An ADC with16 bits has a higher resolution and thus a higher degree of accuracy than a 12 bit ADC Application Development Environment a type of signal conditioning that improves accuracy in the resulting digitized signal and reduces noise a measure of how close to constant the gain of a circuit remains over a range of freque
41. s Commission FCC has rules to protect wireless communications from interference The FCC places digital electronics into two classes These classes are known as Class A for use in industrial commercial locations only or Class B for use in residential or commercial locations Depending on where it is operated this product could be subject to restrictions in the FCC rules In Canada the Department of Communications DOC of Industry Canada regulates wireless interference in much the same way Digital electronics emit weak signals during normal operation that can affect radio television or other wireless products By examining the product you purchased you can determine the FCC Class and therefore which of the two FCC DOC Warnings apply in the following sections Some products may not be labeled at all for FCC if so the reader should then assume these are Class A devices FCC Class A products only display a simple warning statement of one paragraph in length regarding interference and undesired operation Most of our products are FCC Class A The FCC rules have restrictions regarding the locations where FCC Class A products can be operated FCC Class B products display either a FCC ID code starting with the letters EXN Trado Nares 7 Wedel Nunwber or the FCC Class B compliance mark that appears as shown here on the right e UER FC with FCC Standards Consult the FCC web site http www fcc gov for more information FCC DOC Warnings
42. t 2 4 two wire resistance measurements 2 8 to 2 9 circuit figure 2 8 input ranges 2 8 to 2 9 using VirtualBench DMM Soft Front panel 1 6 to 1 7 National Instruments Corporation l 3 Index V VirtualBench DMM Soft Front panel 1 3 to 1 9 current measurement 1 8 DC and AC voltage measurement 1 5 to 1 6 diode measurement 1 7 to 1 8 illustration 1 3 options on front panel 1 3 to 1 5 two wire resistance measurement 1 6 to 1 7 voltage measurement See AC voltage measurement DC voltage measurement W warm up time requirement for NI 4050 2 2 Web support from National Instruments B 1 to B 2 online problem solving and diagnostic resources B 1 software related resources B 2 Worldwide technical support B 2 NI 4050 User Manual
43. t impedance of 100 KQ If you are taking measurements that require a high degree of accuracy you should consider problems associated with input impedance noise effects and thermal electromotive forces thermal EMFs These effects are discussed in the Measurement Considerations section Measurement Considerations Input Impedance Figure 2 1 illustrates the input impedance of an NI 4050 and its effect on the measurement of a circuit under test If you know the source impedance of the circuit being tested you can correct for the attenuation caused by the NI 4050 in software Since R is large at least 1 MQ it will require a large source impedance R to cause a large change in the measured voltage Vp Measured Voltage Vin External Source Impedance R HI Input Source Impedance Input p R VQ Voltage Vs LO Figure 2 1 Effect of Input Impedance on Signal Measurements National Instruments Corporation 2 3 NI 4050 User Manual Chapter 2 NI 4050 Operation NI 4050 User Manual Thermal EMF Thermal EMFs or thermoelectric potentials are voltages generated at the junctions of dissimilar metals and are functions of temperature Thermal EMFs in a circuit under test can cause higher than expected offsets that change with temperature Noise Rejection The NI 4050 filters out AC voltages in the DC voltage measurement ranges However if the amplitudes of
44. ti amiss E EE 2 2 Selecting the Resolution eresesrorersresesterererserersrerereerererseureerererserersrererereere 2 2 GrloundiN aE EEEE ETT adi hadi 2 2 Voltage Measurements nine a aE nE E ESEE EE E TEE R Wevee 2 2 DC Voltage a a E R E e E E ETE a 2 2 Input Range Seii a o ae ena a o ae dee ae 2 3 Measurement Considerations ccesececssceececeeeeessecenceceeeeeneceeeenes 2 3 Input Impedance n r eee eeeeeecereeeseeseecaeceseaecaeeneeneens 2 3 Thermal EME ssc scesieti siceesesiestneais tah a E 2 4 Noise REjECtiOM ics ccseciessiecedees lies n bes 2 4 PCY OMA BC nE EE P ETE E E EEE EE 2 6 Input Ranges e E E E E E 2 7 Measurement Considerations scceseceeseceseeceneeceseceneeceeeeeneceeneenes 2 7 AC Offset Voltage 0 cece n i en e t 2 7 Frequency Response scesccsseeeeseceececeseceseeceneeceaeeeneeesees 2 7 Resistance Measurements ionann eninin ie S E E E E aE 2 8 2 Wire Resistance Measurements ceeceessceececssecesceceneecseceseeeeseeesaeceneeses 2 8 Input Ranges n r A E E 2 8 Continuity Measurements e s eee ee ceeeeeceseecseceecaecseaeceeceseceseeseeeeeeeeeeesenes 2 9 Diode Measurements ieren arn rien iia r T E E EAE S 2 9 National Instruments Corporation vil NI 4050 User Manual Contents Appendix A Specifications Appendix B Technical Support Resources Glossary Index Figures Figure 1 1 Installing the NI 4050 and Cables eee eeeseeeeceseeeeeeeeeeeeeeenees 1
45. ts The database is updated daily in response to new customer experiences and feedback e Troubleshooting Wizards Step by step guides lead you through common problems and answer questions about our entire product line Wizards include screen shots that illustrate the steps being described and provide detailed information ranging from simple getting started instructions to advanced topics e Product Manuals A comprehensive searchable library of the latest editions of National Instruments hardware and software product manuals e Hardware Reference Database A searchable database containing brief hardware descriptions mechanical drawings and helpful images of jumper settings and connector pinouts e Application Notes A library with more than 100 short papers addressing specific topics such as creating and calling DLLs developing your own instrument driver software and porting applications between platforms and operating systems National Instruments Corporation B 1 NI 4050 User Manual Appendix B Technical Support Resources Software Related Resources e Instrument Driver Network A library with hundreds of instrument drivers for control of standalone instruments via GPIB VXI or serial interfaces You also can submit a request for a particular instrument driver if it does not already appear in the library e Example Programs Database A database with numerous non shipping example programs for National Instruments prog
46. ts and stops continuous DMM measurements The single button performs a single measurement The math buttons allow you to manipulate readings mathematically Null starts relative mode VirtualBench DMM makes all subsequent measurements relative to the measurement it makes when you click on Null Max Min displays the maximum and minimum values that occur after you start Relative mode mX B enables the mX B calculation on all readings dB compresses a large range of measurements into a much smaller range by expressing DC or AC voltage in decibels dBm shows decibels above or below a 1 mW reference 1 4 www ni com Chapter 1 Taking Measurements with the NI 4050 selects the percentage calculation VirtualBench DMM expresses the 2 displayed reading as a percent deviation from the reference value entered in the Math Settings Refer to Help Online Reference Math Settings topic for more information about dB dBm mX B and percentage calculations a The log button enables data logging To configure the datalog file and log interval select Edit Settings Refer to Help Online Reference Logging Measurements to Disk topic for more details Digits of Precision A pop up ring control in the DMM front panel display allows you to set measurement accuracy to 3 1 2 4 1 2 or 5 1 2 A larger value gives greater precision but slower measurement performance Refer to Figure 1 3 LJ irtualbench UMM File Edit Window Uvility H
47. uired in an analog input or output system from the moment a channel is interrogated such as with a read instruction to the moment that accurate data is available the manner in which a signal is connected from one location to another central processing unit the ratio of the peak value of the signal to the RMS value of the signal current shunt module data acquisition 1 collecting and measuring electrical signals from sensors transducers and test probes or fixtures and inputting them to a computer for processing 2 collecting and measuring the same kinds of electrical signals with A D and or DIO boards plugged into a computer and possibly generating control signals with D A and or DIO boards in the same computer decibel the unit for expressing a logarithmic measure of the ratio of two signal levels dB 20log10 V1 V2 for signals in volts direct current a default parameter value recorded in the driver In many cases the default input of a control is a certain value often 0 that means use the current default setting a plug in data acquisition board card or pad that can contain multiple channels and conversion devices Plug in boards PCMCIA cards devices such as the DAQPad 1200 which connects to your computer parallel port are all examples of DAQ devices G 3 NI 4050 User Manual Glossary dielectric absorption differential input DMM DNL double insulated drivers ECMR EEPROM EXT TRIG IN F
48. voltage specifications A 1 diagnostic resources online B 1 National Instruments Corporation diode measurement circuit figure 2 9 description 2 9 using VirtualBench DMM Soft Front panel 1 7 to 1 8 diode testing specifications A 5 E effective common mode rejection 2 6 environment specifications A 6 F frequency response AC voltage measurement 2 7 to 2 8 G grounding the NI 4050 2 2 input impedance DC voltage measurement 2 3 input ranges AC voltage measurement 2 7 DC voltage measurement 2 3 two wire resistance measurements 2 8 to 2 9 measurement AC voltage 2 6 to 2 8 AC offset voltage 2 7 frequency response 2 7 to 2 8 input ranges 2 7 NI 4050 User Manual Index using VirtualBench DMM Soft Front panel 1 5 to 1 6 current 1 8 DC voltage 2 2 to 2 6 common mode rejection 2 6 to 2 7 effective common mode rejection 2 6 input impedance 2 3 input ranges 2 3 noise rejection 2 4 to 2 6 normal mode rejection 2 4 to 2 5 thermal EMF 2 4 using VirtualBench DMM Soft Front panel 1 5 to 1 6 diode circuit figure 2 9 description 2 9 using VirtualBench DMM Soft Front panel 1 7 to 1 8 fundamentals of measurement grounding 2 2 selecting resolution 2 2 warm up time 2 2 resistance 2 8 to 2 9 continuity 2 9 two wire 2 8 to 2 9 circuit figure 2 8 input ranges 2 8 to 2 9 using VirtualBench DMM Soft Front panel 1 6 to 1 7 temperature 1 9 National Instruments Web sup
49. y 1 Year Temperature Coefficient Range 25 C 41 C 25 C 10 C 25 C 10 C of Reading C mA C 200 000 mA 0 45 0 22 mA 0 47 1 2 mA 0 47 1 2 mA 0 007 0 110 mA 20 0000 mA 0 35 110 pA 0 37 170 pA 0 37 170 pA 0 019 0 120 mA 10 0000 A 0 3 22 mA 0 32 120 mA 0 32 120 mA 0 026 11 mA Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linerarity and noise Requires 200 mA shunt CSM 200mA Requires 10 A shunt CSM 10A Input Characteristics 200 mA shunt Input protection oe eee Fuse F1 500 mA 250 V fast fusing Shunt resistor eee eee eeeeeeeee 10 Burden voltage lt 400 mV at 200 mA 10 A shunt Input protection oe eee Fuse F1 12 5 A 250 V fast fusing Shunt resistor eee eee cece 10 mQ Burden voltage eee eee lt 300 mV at 10 A NI 4050 User Manual A 4 www ni com Appendix A Specifications Resistance Accuracy of reading Q 24 Hour 90 Day 1 Year Temperature Coefficient Range 25 C 1 C 25 C 10 C 25 C 10 C of Reading C Q C Extended Ohm 0 1 6kQ 0 1 60 KQ 0 1 60 kQ 0 0072 6kQ gt 2 MQ 2 00000 MQ 0 012 55 Q 0 077 370 Q 0 080 20 Q 0 0072 35 Q 200 000 kQ 0 012 37 Q 0 077 350 Q 0 080 2 Q 0 0072 35 Q 20 0000 kQ 0 006 0 5 Q 0 024 4 Q 0 027 4 Q 0 0020 0 40 Q 2 00000 kQ 0 006 0 4 Q 0
50. y result in different readings for the same diode HE le O Input Vsense O D i VQ VW Vaiiode ex LO w Vsense Viiode Figure 2 5 Circuit for Diode Measurements National Instruments Corporation 2 9 NI 4050 User Manual Specifications This appendix lists the specifications of the NI 4050 These specifications are guaranteed between 15 and 35 C unless otherwise specified DC Voltage Accuracy of reading uV 24 Hour 90 Day 1 Year Temperature Coefficient Range 25 C 41 C 25 C 10 C 25 C 10 C of Reading C pV C 250 000 V 0 0032 4 9 mV 0 021 49 mV 0 024 49 mV 0 0017 4800 uV 25 0000 V 0 0032 4 9 mV 0 021 49 mV 0 024 49 mV 0 0017 4800 uV 2 00000 V 0 0029 37 uV 0 014 260 uV 0 017 260 uV 0 0009 25 uV 200 000 mV 0 0029 27 uV 0 014 250 uV 0 017 250 uV 0 0009 25 uV 20 0000 mV 0 0029 27 uV 0 014 250 uV 0 017 250 uV 0 0009 25 uV Accuracy numbers are for 5 1 2 digits and include the effects of full scale and zero scale errors temperature variation linearity and noise Noise Rejection NMRR 10 Hz reading rate 50 60 Hz powerline frequency 1 DC ECMRR AC ECMR RDC to 60 Hz P S 140 dB with a 1 KQ imbalance in LO lead PEE 150 dB with a 1 kQ imbalance in LO lead Input Characteristics Input bias
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