Agilent Technologies 34411A Specifications
Contents
1. e Small bench top foot print e Easy to use interface e Dual displays for setup and measurements e Enhanced probe kit for surface mount parts e DCV DCI ACV ACI Freq Period 2 4 wire e Diode testing and continuity e Precision capacitance measurements e Offset compensated resistance measurements e Temperature measurements thermistor and RTD e Peak measurements while measuring DC or AC signals e Statistical math at maximum sample rate e Limit checking with analog like status on display e Simple data logging to non volatile memory e Built in Web server e Intuilink software for Excel spread sheets In today s electronic world surface mount resistors and capacitors are very small and unmarked If you have a DMM with a high quality set of surface mount probes you can make precision capacitance measurements which will help you re categorize that pile of parts lying on your bench Peak measurements while per forming precision DC or AC measurements is a significant troubleshooting tool The built in data logging wizard allows you to pick any function set up the timing and let the DMM make unattended measurements while storing them into non volatile memory With a LAN connec tion to your PC the built in Web server makes it easy to cut and paste readings directly into your spread sheet or you can use the supplied IntuiLink software for simple data logging from USB LAN or GPIB2. IVI Interchangeable virtual instrument Oriented towards having programming routines that can be used for any vendor s DMM NMR Normal mode rejection Usually related to rejecting power line frequency noise NPLC Number of power line cycles Power line is usually 50 Hz or 60 Hz but it can be 400 Hz Related Agilent literature Data sheets 5989 3738EN Agilent 34410A 34411A 6 12 Digit Multimeters Application notes 5989 4038EN Replacing the Agilent 34401A with the New Agilent 34410A and 34411A High Performance Digital Multimeters You can get copies of these publications at www agilent com find 34410a Agilent Technologies Test and Measurement Support Services and Assistance Agilent Technologies aims to maximize the value you receive while minimizing your risk and problems We strive to ensure that you get the test and measurement capabil ities you paid for and obtain the support you need Our extensive support resources and services can help you choose the right Agilent products for your applications and apply them successfully Every instrument and system we sell has a global warranty Two concepts underlie Agilent s overall support policy Our Promise and Your Advantage Our Promise Our Promise means your Agilent test and measurement equipment will meet its advertised performance and functionality When you are choosing new equipment we will help you with product information i
3. The electric current passing through the low pressure gas emits UV light The internal phosphor coating efficiently converts most of the U V to visible light Once the initial discharge takes place a much lower voltage usually a voltage from 100 VAC to 175 VAC is needed to main tain the discharge dependent upon the wattage rating of the bulb A DMM is needed to test the ballast voltages to assure the correct voltages are being applied This is an ACV mea surement Many DMMs including the Agilent 34401A use an analog RMS converter for ACV measurements Although these converters can measure frequency content as high as 1 MHz they do not do a very good job of telling the DMM that short duration high voltage spikes may be present on the input These short spikes may have little impact on RMS content so the resulting voltage measurement may hardly deviate from the expected voltage Initial Discharge 300 VAC Steady State 100 VAC Figure 3 Ballast voltage needed to start a fluorescent bulb and then keep it lit For example the ballast may actually generate 1 kV or higher spikes along with the 300 VAC signal needed for initial startup The DMM may read 300 VAC and occasionally 301 VAC The test system thinks that is just fine well within tolerance However you do not see the huge voltage spikes pounding against the input section of the DMM If the DMM does not have effective i
4. in the switch and is configured to sequence through channels when a pulse is received on its channel advance The channel Figure 8 Agilent 34980A switch measure unit and 34410A DMM list is initiated and the switch will close the first channel in the list to begin the process When the first channel in the list is guaranteed closed the switch instrument s channel closed output is pulsed That pulse triggers the DMM When the DMM is finished looking at the input signal it will pulse its voltmeter complete output This causes the current channel to open and the next channel to close The cycle is repeated until all channels have been scanned Programming exam ples are included with the 34410A 34411A CD and at www agilent com find 34410A that show how to use an external DMM to scan channels with the 34980A switch measure unit The 34410A and 34411A use a fast auto ranging technique that makes scanning a wide variety of signal levels virtually as fast as most switches can scan Voltmeter complete and external trigger levels can be set as positive or negative going pulses to accommodate virtually any external switch instrument If necessary an additional delay can be pro grammed into the sample rate of the DMM in order to permit additional time for input signals to settle before the DMM actually makes measurements Understanding Fast Measurements Some of the examples in the previous section require pro
5. in the system reading architec ture diagram See Figure 11 e Path A this is the reading rate into reading storage Top speed into memory is 50 000 readings s which is a function of the A to D sampling rate Any measure ment DC or AC will generate a pulse on the voltmeter complete signal of the DMM That signal can be used to measure all sample rates on a scope or frequency counter DMM input 34410A 34411A DMM memory DMM 50 k readings non volatile Figure 11 System Reading Architecture e Path B this is the time it takes to retrieve readings from reading storage DMM memory to PC This speed is dependent both upon the data format and the interface Data format can be ASCII 15 bytes binary 32 4 bytes or binary 64 8 bytes Inter faces include the physical interfaces of GPIB LAN and USB 2 0 and also LAN VXI 11 or sockets e Path C this is the time it takes to programmatically trigger a reading or readings and retrieve the results into a computer Single reading times are shown in the direct I O table and represent a READ command which is the same as the INIT FETCH command Since the data rates are so fast when you use binary format the PC can keep up with any sample rate by simply issuing requests for blocks of readings at periodic times while making continuous measurements at up to 50 000 readings s rate Only two modes are not fast enough to kee
6. Key features for system use Remove the rubber bumpers and handle and you have a system ready DMM that can outperform even VXI and PXI instrumentation You get higher throughput in high volume manufacturing for applications such as wireless handsets wireless LAN Bluetooth and automotive testing Key features for the system user e Front and rear input terminals e Easy to use SCPI command language e Up to 50 k readings s continuous to PC e Traceable accuracy in addition to fast measurements e Retrieve readings up to 270 000 s from reading storage e Sub millisecond command parsing e Sub microsecond external trigger latencies e Hardware handshake to switch instruments e Precision sample timer for waveform capture e Peak measurements while measuring DC or AC signals e 100 Mbit LAN USB 2 0 and GPIB e Web server for remote access e LXI Class C compliant e 34401A emulation mode e Drivers for IVI and LabVIEW These DMMs are system ready you turn them on and they re ready for operation from the front panel or through a Web browser You don t have to install drivers before you can even use the instrument Having a built in Web server gives you complete control of the DMM from any computer that has a LAN port If you can connect to eBay com you can connect to these DMMs without the need for any driver software Developing programs is almost as easy The DMMs come with Agilent s powerful
7. VISA I O library drivers and examples for the most popular programming development environments so you are programming within minutes not hours If you are considering replacing the 34401A in your test system all you need to do is put the 34410A or 34411A in emulation mode using the SYSTem LANGuage 34401A command You do not have to rewrite your tests except to compensate for a much faster instrument and higher resolution measure ments This mode is retained in nonvolatile memory so when you cycle power the DMM still thinks it is a 34401A Please refer to Application Note 5989 4038EN Replacing the Agilent 34401A with the new Agilent 34410A and 34411A High Performance Digital Multimeters Applications and Solutions Whether your application requires general purpose measurements precision DC and AC measurements waveform capture of mechanical electrical signals or fast throughput and programming speed these new DMMs have the measurement capability you need This section gives you examples that demonstrate some of the newer capabilities not found in many general purpose DMMs The next section Understanding Fast Measurements will show you how to configure your DMM for these measurements Precision measurements with high NMR The 34410A and 34411A use a special aperture shaping algorithm to increase normal mode rejection NMR of power line related noise in DC measurements It is an
8. duced using this time domain straight line approximation technique The 34410A and 34411A use a patented time domain algorithm to reject some of the non ideal performance charac teristics of capacitors First and foremost the A to D is able to sample fast enough to capture multiple points on the charge ramp of the capacitor under test without introducing significant noise to the mea surement Second the constant current source does not have substantial non ideal behaviors such as a thermal tail when turning on Third the internal capacitance of the DMM and lead capacitance of the probes can be calibrated out using the built in math null function which subtracts the initial mea surement from all subsequent measurements Substantial improvements in accuracy are attained using this technique The 34410A and 34411A DMMs can actually perform much better than their 0 5 specifications In lab testing on a high accuracy capacitance standard these DMMs achieved a performance level on the order of 0 1 Furthermore measure ments of capacitors with poor dielectrics such as aluminum electrolytic capacitors showed greatly improved accuracy Simple data logging without a PC Let s say your boss stops by just before you leave for lunch and asks you to measure temperature changes in the computer server room He suspects the air conditioner is generating rapid and wide changes in temperature How can you get this
9. line related but they can be associ ated with higher frequency byproducts of switching power supplies For example Figure 1 shows a DC signal with an AC component A common approach to this measurement problem is to make both a DCV and ACV RMS measurement However there are limitations to this approach e Making two measurements takes more time especially changing function and range e A typical ACV RMS measure ment lacks valuable peak information e Having to digitize to get peak information takes time Figure 1 A 5 V DC signal with an AC signal The 34410A and 34411A DMMs provide a secondary measurement function called peak measurements that you can activate when you make precision DCV or ACV measurements Here is an improvement on the above approach e Enable the peak measure ment function e Make a precision DCV measurement using 1 or more periods of power line cycle integration time to reject power line frequencies and random noise e The DCV and peak measure ment data is displayed Peak measurements occur at 20 us intervals during the aperture of the DCV measure ment so any peak that is at least 20 us wide can be detected Several scenarios that can be determined from the two mea surements 1 The DCV and peak to peak data are within tolerance passed 2 The DCV is correct but the peak to peak value exceeds a limit failed 3 The DCV is slightly off
10. of 2 5 kHz The 34411A provides waveform capture for these types of signals using the following capabilities e 50 kHz sample rate at 4 5 digits using a low jitter sample timer e Bandwidth response relatively flat lt 0 1 dB at 3 kHz lt 0 6 dB at 8 kHz e Analog level trigger e Pre and post trigger sampling e 1 million reading storage e 270 k readings s access to reading storage Electronic signals generated in functional test applications also are often below 8 kHz voice signals of 300 Hz to 3 kHz battery drain in handheld devices such as cell phones cameras or PDAs and other low frequency content signals The measurement of current drain in handheld devices is commonplace in the electronics industry Long battery life is a key factor in customer satis faction It is important to understand the current drain for various operations of a handheld device Some Agilent power supplies can sample accurately at microampere levels the current waveform supplied to a device under test The Agilent N6700 power supplies provide this capability However the mea surement is limited to the cur rent coming out of the supply Once a test system determines that too much current is being drawn from the battery a number of other test points are typically tested to see which sections of the hand held device are on when they should or should not be on and for how long This test requires waveform capture to check the ti
11. started quickly and still meet your lunch date on time e Grab your 34410A probe and power cord and bring them to the computer room e Position the sensor probe e Select the temperature measurement function and sensor type e Press the Data Log key and set up l second intervals for an hour e Press the Trigger key to start the process e Go to lunch When you return from lunch the measurements are com plete Or if an hour has not passed you can stop the data logging process by pressing any key for a prompt Either way your readings are stored in non volatile memory Now finish up e Unplug the DMM and carry it back to your office e Hook up the LAN and start your PC s browser e Cut and paste readings from the browser into your spread sheet e Print out the chart or graph and submit it to your boss Reset Utility Auto Rng 2nd Data Disp Log Math Auto Trig Local Key points e You did not have to drag a computer along to set up measurements e Set up was very easy from the front panel e The 34410A is small and easily transportable e You did not need to write or load a program to gather the data Precision DCV measurements combined with peak measurements Power supplies often have ripple voltages that are riding on top of the desired DC output These ripple voltages are speci fied and tested to be a certain level or less Frequencies of the AC signal are often power
12. 0 V range The following table shows how noise affects resolu tion of different measurement functions Operating Characteristics Maximum readings second Digits Function 45 5 5 6 5 DCV 50 k 10k 1k 2 wire Q 25 k 3k 60 DCI 3k 60 60 ACV 500 500 150 ACI 500 150 150 Frequency 450 90 10 Period 450 90 10 For the 34411A note that 50 k readings s is specified at 4 5 digits for DCV but it is only 3 k readings s with DCI A speed reduction is also recommended and occurs with resistance measurements This does not limit measuring current or resistance at 50 k readings s It simply means that Agilent has chosen to show readings rates only for the 4 5 5 5 and 6 5 digits resolutions In applications like automotive electronic test 3 5 or 4 digits of resolution may be more than adequate so higher sample rates are useful One way to make faster higher resolution DCI measurements at guaranteed higher resolution is to use an external current shunt and sample the shunt resistor using DCV at 50 k readings s A 1 ohm resistor gives 0 001 V at 1 mA so very precise measurements can be made at high resolutions How to set up the DMM for fast DC measurements There are a five key factors that control measurement speed for DC measurements e Autozero e Autorange e Aperture e Automatic trigger delay e Peak measurements When you use autozero auto range and peak measurements you engage an int
13. 1A have two triggering models The models are illustrated in Figure 10 When you use the SCPI com mands shown in the previous section the count and delay pacing model is implied If the trigger delay is zero the next measurement will begin immediately after the previous measurement This model is particularly useful for general purpose measurements especially if you want to use autorange That is you set up the DMM to run as fast as it can and you don t worry about how long each measurement is taking However this model is not good for waveform capture since the constant trigger delay occurs after a measurement is completed The precision sample timing model is used to perform waveform capture In this case the sample period is set to a value less than or equal to the interval As long as the sample period does not exceed the interval predictable time placement of measurements takes place Note that trigger delay is now a separate para meter and is only used at the beginning of the burst of measurements With this model using autorange is VOLT RANGE 1 0 1 CONF VOLT DC Count and Delay Pacing Trigger Trigger Sample 1 Trigger Sample 2 Trigger Sample 3 Delay Delay Delay Precision Sample Timing Trigger Interval Interval Interval Trigger Sample 1 Sample 2 Sample 3 Delay Figure 10 Multimeters can pace samples by using just a delay top or by using a p
14. ACI 2 4 wire ohms e Frequency period continuity and diode test e Capacitance and temperature measurements e Wide measurement ranges e Data logger with 50 k reading non volatile memory Agilent 34411A 61 2 digit enhanced performance DMM All the features of the 34410A plus e 50 000 readings s at 41 2 digits e 1 million reading memory e Analog level triggering e Programmable pre post triggering gt Agilent Technologies The 34410A and 34411A are backward compatible with the Agilent 34401A multimeter and support a 34401A emulation mode You will find a detailed comparison of the 34401A with the new 34410A 34411A DMMs in Application Note 5989 4038EN Replacing the Agilent 34401A with the New Agilent 34410A and 34411A High Performance Digital Multimeters A number of performance specifications are called out in this application note however please refer to the 34410A 34411A multimeter data sheet publication number 5989 3738EN for specifics on overall measurement and system performance Overview of Features and Performance Both the 34410A and 34411A are excellent bench top and system DMMs They are designed to be the best of both worlds and provide a very consistent path from the R amp D bench envi ronment into design validation and manufacturing Key features for bench top testing As bench DMMs the 34410A and 34411A provide expanded R amp D characterization functions and features
15. Contents Introduction 1 Features and Performance 2 Applications and Solutions 4 Understanding Fast Measurements 13 The Advantages of a 18 Built In Web Server Conclusion 19 Glossary 19 Agilent 34410A 34411A 61 2 Digit High Performance Multimeters Application Note Introduction The Agilent 34410A and 34411A are the latest generation of 61 2 digit multimeters from Agilent Technologies The 34410A and 34411A are general purpose DMMs that give excellent price performance in a wide range of applications Each DMM builds upon the success of the industry standard Agilent 34401A and each offers significantly enhanced functionality for bench and system users Whether your application is in electronic components aerospace communications automotive industrial or one of the many other industries that require DC and AC mea surements you will find that the 34410A and 34411A DMMs offer you the performance you need and are easy to use This application note gives you a detailed look at how you can use the features and performance of these new DMMs in a variety of applications to overcome measurement challenges a ee n e A 5299006 So x QGIOoe0S9 a Key features Agilent 34410A 61 2 digit high performance DMM 10 000 readings s at 51 digits 1 000 readings s at 61 2 digits e 30 PPM 1 year basic DC accuracy e LAN USB and GPIB standard DCV ACV DCI
16. applications e Log capture SCPI commands from any interface e Learning tool to understand how to program the DMM e Remote passive monitoring of test system measurements One of the most powerful capabilities of the Web server aside from an even easier to use interface and passive monitoring while in a test system is the SCPI command logging feature You literally don t need a manual to learn how to program the DMM Using the command logging capability of the Web server every configuration you make from the browser will create an associated SCPI command sequence that shows how to configure the DMM program matically You simply cut and paste the SCPI commands from the browser window into your program This capability is found under DMM Overview and the Read Clear Remote I O Traffic Log selection Conclusion The 34410A and 34411A DMMs offer superior ease of use on the bench and they offer blistering performance for test system applications Whether your application requires general purpose measurements preci sion DC and AC measurements waveform capture of mechanical electrical signals or fast throughput and programming speed the 34410A and 34411A offer measurement capabilities that make them ideal tools for a broad range of applications Glossary SCPI Standard commands for pro grammable instrumentation This is an English style language that has been used in instrumentation for many years
17. but the peak to peak value is OK failed In cases 2 and 3 the peak to peak ripple voltage is in question Case 2 may be excessive noise spikes due to failed output filtering Case 3 could be distortion that is creating an asymmetrical AC component that adds a DC component to the DCV measurement In that case the ripple may retain the same peak to peak voltage When the primary measurement fails more information about the signal is required The 34411A DMM provides wave form capture at 50 k readings s that can sample the signal to provide additional diagnostic information In manufacturing the goal is to minimize test time so the combination of precision DCV and peak measurements can significantly reduce test time compared to making individual DCV and ACV measurements or digitizing and processing the signal The additional benefit is obtaining the peak to peak information which can better indicate the quality of the power supply s output signal Precision measurements with level triggering The following waveform Figure 2 represents the current drain of a battery during an operation in a hand held device The goal is to measure the average DC value of the pulse but only during the duration of the pulse This pulse has no associated 5 V logic signal event that can be used as a synchronous external trigger At first it would seem that capturing the asynchronous event with a large number of high speed measureme
18. d readings can be retrieved either continuously at the 50 k rate or in bursts of up to 270 k readings second from each 34411A s reading storage For this particular application the four DMMs may be borrowed from colleagues It is easy to set up a number of instruments with complimentary triggering and the 100 Mbit LAN or USB 2 0 interfaces can easily keep up with the combined data rates External Trigger Effectively 200 k Samples s 34411A DUT Figure 7 Making simultaneous measurements on a DUT using multiple multimeters 11 External DMM connected to switch The fastest and most convenient way to scan through a list of channels is to hardware couple the DMM directly to a switch instrument like the Agilent 34980A switch measure unit Once you start a scan the switch and DMM communicate without any intervention from the PC This is much faster than trying to sequence channels using software commands Most switch instruments imple ment a channel closed output and a channel advance input e Channel closed a pulse is output when a channel is guaranteed closed e Channel advance a pulse received advances to the next channel in the list When using an external DMM the voltmeter complete line of the DMM is connected to the channel advance of the switch The external trigger input of the DMM is connected to the channel closed output of the switch A channel list is created
19. e Automatic trigger delay All AC measurements are limited to 500 readings s or less Measurements can be slower dependent upon the settings of these three factors AC filter is common to all AC measurements and is the most significant factor The response of the filter affects measurement speed See the table below Maximum Reading Rate 50 readings second 20 Hz 300 kHz Medium 0 625 second reading 167 readings second 200 Hz 300 kHz Fast 0 025 second reading 500 readings second The default setting when using the automatic trigger delay is shown If the trigger delay is set to zero the maximum reading rate is possible Autorange does not significantly impact the measurement speed until a high voltage signal causes an actuator relay to change ranges The automatic trigger delay slows down the measure ment speed based mainly upon the selection of the AC filter SCPI command example to achieve maximum measurement speed for ACV CONF VOLT AC VOLT AC BAND 200 VOLT AC RANGE 1 0 TRIG DELAY AUTO OFF TRIG DELAY 0 ACI will use the same com mands except for specifying CURR instead of VOLT For frequency the FREQ APER command specifies a gate time of 0 001 0 01 0 1 or 1 second which will also affect reading rates in addition to the AC filter selection Peak to peak measurements do not slow down AC RMS measurements How to set up various triggering scenarios The 34410A and 3441
20. ernal software state machine to control operations inside the DMM This state machine is limited to about 2000 readings s best case To achieve readings rates higher than 2 k readings s the internal state machine must be disengaged by turning off autozero selecting a fixed range and disabling peak measurements Autozero occurs after each measurement of the applied signal Internal circuitry disen gages the applied signal and shorts the path from the input terminal to the A to D Any off set is measured and subtracted from the actual measurement This means there are two readings taken for every mea surement Turning autozero off saves time because you make only a single measure ment and do not engage the software state machine Autorange makes pre measure ments of the applied signal to try and determine the best range to select in order to achieve the highest resolution measurement Autorange is very fast in these DMMs and can easily track a 120 Hz signal Autorange will also take longer when transi tioning from the 10 V or 10 Mohm ranges to higher ranges Turning autorange off will disengage the software state machine Aperture is the time the A to D spends integrating the applied signal The minimum DC apertures for the 34410A and 34411A are 100 us and 20 us respectively Aperture resolu tion is 20 us therefore the highest sample rate for the 34411A is 50 k readings s 20 us aperture The next high
21. est rate is 25 k readings s 40 us aperture The automatic trigger delay is a programmed setting that is enabled by default When enabled the DMM determines the recommended delay based upon function range and integration time or aperture time This delay is associated with the trigger subsystem If disabled it is disabled for all functions Peak measurements are designed to be used when making precision DC measure ments In those cases the aperture of the measurement is usually 1 or more PLCs Peak measurements can be enabled with 6 5 digit DC measurements and still achieve 1000 readings s SCPI command example to achieve maximum measurement speed for DCV CONF VOLT DC VOLT ZERO AUTO OFF VOLT RANGE 1 0 VOLT APER MIN or VOLT NPLC MIN TRIG DELAY AUTO OFF TRIG DELAY 0 The aperture setting is set to MIN For the 34410A this would be 100 us For the 34411A 20 us is the MIN The same commands can be used for DCI ohms or temperature but you have to change the VOLT to CURR RES FRES or TEMP Autozero cannot be turned off when making four wire ohms measurements Temperature measurements are all resistive and can be two or four wire measurements Input Frequency 3 Hz 300 kHz Slow Default Settling Delay 2 5 seconds reading How to set up the DMM for fast AC measurements For AC measurements the following are the key factors in measurement speed e AC filter setting e Autorange
22. gramming the DMM to its fastest measurement settings and using the trigger subsystem Depending on the requirements of your application the fastest rate may not achieve the desired performance For example if measurements are made with an aperture less than 1 PLC and in the presence of signifi cant power line frequency interference there is no normal mode rejection NMR at those frequencies Any rejection of such interference would have to occur through averaging readings in the computer and many samples must be taken over the period of the noise to reject To sample faster than 1 PLC in the presence of noise the typical solution is to add passive filtering to the sensors before they are measured by the DMM Resolution also can be reduced when you are making fast measurements For the 34410A and 34411A the reduction is based on noise performance of the A to D and input circuits All DMMs have such noise in varying degrees The 34410A and 34411A have industry leading performance in measurement speed versus RMS noise The chart in Figure 9 shows the entire measurement speed spectrum of both DMMs from 0 001 NPLC 50 k read ings s to 100 NPLC 100 gt u RMS Noise ppm of range 0 01 0 001 0 01 0 1 1 10 100 Integration Time NPLC Figure 9 The entire measurement speed spectrum of the 34410A and 34411A DMMs This chart represents straight through signal processing the 1
23. increasing and decreasing series of weighted averages of multiple measurements This special algorithm is utilized on NPLC settings of 2 10 and 100 At 1 PLC the NMR is specified as 55 dB but at 2 PLC the rejection leaps to 110 dB at 0 1 of the power line frequency Most DMMs provide only 60 dB of rejection at 10 and 100 NPLC settings and 0 1 of deviation from line frequency However the shaped aperture algorithm creates a wider notch of operating frequency and achieves 75 dB at 1 and 55 dB at 3 This allows higher precision measurements at faster rates than is available from most other DMMs on the market Precision capacitance measurements When you are designing circuits it is highly advantageous to know the actual value of a capacitor to be used in a circuit Hand held multimeters and most 512 digit multimeters typically use a measurement technique that assumes an ideal capacitor being charged by an ideal constant current source to determine capacitance with the formula C I dV dt These instruments then specify an error of 1 or more for film capacitors polyester and polypropylene dielectrics but do not specify errors for capacitors of other dielectrics Real world capacitors exhibit non ideal behavior due to dielectric absorption leakage dissipation factor and nonlinear equivalent series resistance ESR Current sources are not ideal either so a substantial amount of error can be intro
24. ming of current usage The waveform in Figure 4 is the current drain from a cam era that has just been actuated to take a picture In this case this is the voltage across a cur rent shunt Represented in the waveform are the mechanical movements of the auto focus processing the picture driving the display and status LED s and storing the result in flash memory Level Trigger ne ne et nf MI un TTA RR 3 seconds Wh i lt Pre Trigger Post Trigger Count Count HAY i rene Figure 4 Using level triggering to digitize current drawn from a digital camera battery The 34411A level trigger is specified in units of any mea surement function In this case a DCV measurement is being made at 50 k samples s With 1 million readings 20 seconds of data can be stored at this rate Pre and post triggering allows you to create a scope like capture of the waveform around an event The DMM will continuously make measurements until the level trigger is met It will retain the pre trigger count of measurements and then begin the count of post trigger mea surements This is an excellent alternative to waiting for an asynchronous event and there is no discontinuity of measure ments between pre and post trigger counts Delayed sampling from occur rence of an external trigger In many applications you need to wait a period of time before actually making a measurement a
25. ncluding realistic performance specifica tions and practical recommendations from experienced test engineers When you receive your new Agilent equipment we can help verify that it works properly and help with initial product operation Your Advantage Your Advantage means that Agilent offers a wide range of additional expert test and measurement services which you can purchase according to your unique technical and business needs Solve problems efficiently and gain a competitive edge by contracting with us for calibration extra cost upgrades out of warranty repairs and on site education and training as well as design system integration project management and other professional engineering services Experienced Agilent engi neers and technicians worldwide can help you maximize your productivity optimize the return on investment of your Agilent instruments and systems and obtain dependable measurement accuracy for the life of those products ia Agilent Email Updates www agilent com find emailupdates Get the latest information on the products and applications you select Agilent Direct www agilent com find agilentdirect Quickly choose and use your test equipment solutions with confidence Agilent Open Agilent Open Connectivity Agilent Open is a versatile combination of test system hardware 1 0 and software tools It accelerates the creation of streamlined test systems that are easy to enhance and main
26. nput protection the input circuitry can eventually fail after continued abuse The 34410A and 34411A use a direct sampling technique to make AC RMS measurements Relative to analog RMS calcu lations the direct sampling technique offers four primary advantages 10 times faster AC measurements improved accuracy for high frequency sinusoids peak to peak infor mation and no crest factor de rating Significant over sampling of the input signal can detect the narrow high voltage spikes and the DMM can then respond to those spikes with an overload error condition This informs the test engineer that a problem exists either in the wiring connections to the DMM or in the ballast The solution can be as simple as adding filtering in the fixture to suppress expected spikes before arriving at the input terminals of the DMM Either way the test engineer is better informed by a DMM that can see that actual content of the signal Direct sampled AC provides that visibility into signal content so both RMS and peak measurements can be made simultaneously Level triggering with scope like waveform capture Aerospace and automotive applications are replete with mechanical electrical signals There are mechanical parts that oscillate vibrate and experience tension or compres sion The frequency content of these signals is relatively low often less than 8 kHz For example a typical accelerometer will have a bandwidth
27. nts followed by processing the waveform in a computer to come up with the result would be the only solution This is a relatively simple mea surement to make for a DMM that has analog level triggering No external TTL pulse is needed to start the measurement The 34411A is set to trigger at some point on the rising edge of the pulse a percent of range A trigger delay can be used to make sure the measurement starts on the flat portion of the pulse and the A to D aperture is set to a value that maximizes the precision of the measurement without exceeding the duration of the pulse width In the example a 100 us delay from the level trigger will place the beginning of the measure ment past the rising edge Using a l ms aperture the 34411A can make a 6 2 digit measurement In addition any DC measurement allows the use of the peak measurement function to capture the peak to peak content as shown in the previous example Trig Delay gt lt 100 us 1 ms aperture S Pk Pk 4 Level Trigger Starts Measurement PA Average DC Figure 2 Peak detect occurs at 20 us intervals over the duration of the measurement aperture Testing fluorescent ballasts using direct sampled ACV When a fluorescent lamp is off the mercury gas mixture within the tube is non conductive When power is first applied 300 VAC is needed to initiate a gas dis charge of mercury radiation
28. p up with 50 000 readings s ASCII and 64 bit binary over GPIB DMM memory to PC Maximum reading rate out of memory Drawing Path B Reading GPIB USB 2 0 LAN VXI 11 LAN Sockets Format Readings s Readings s Readings s Readings sec ASCII 2 850 2 000 4 800 4 000 32 bit Binary 89 000 265 000 110 000 270 000 64 bit Binary 47 000 154 000 60 000 160 000 Direct 1 0 Measurements Single reading measure and 1 0 time Drawing Path C Maximum Reading Rate into Memory Function Resolution GPIB USB 2 0 LAN LAN or to Direct 1 0 NPLC ms ms VXI 11 Sockets Readings secs ms ms Drawing Path A or C DCV 2 wire 0 006 0 001 3 0 3 6 5 0 3 5 10 000 50 000 Resistance ACV Fast Filter 10 0 10 0 10 0 10 0 500 Frequency 1 ms Gate 1 2 scale input signal immediate trigger trigger delay 0 auto zero off auto range off no math null off 60 Hz line frequency Specifications are for 34410A or 34411A See manual for performance on other functions The Advantages of a Built In Web Server The 34410A and 34411A have a built in Web server that provides a very powerful configuration diagnosis and programming tool All you need is a LAN connection Web browser and the DMM s IP address If your computer can access eBay com you can access a 34410A 11A from anywhere You need no other software to completely configure the DMM The DMM can be configured for DHCP obtain an IP address from a external hos
29. recise timer bottom not a good idea since you don t really know when the measurement will begin or end Samples that exceed the interval will cause a warning that timing is not met which simply means you are no longer precisely pacing all measurements Here is an example of using the precision sampling trigger subsystem All measurements are stored in reading storage DCV at 50 k readings s an initial 1 ms trigger delay and external trigger VOLT ZERO AUTO OFF VOLT APER 20e 6 TRIG DELAY AUTO OFF TRIG DELAY 1e 3 TRIG SOUR EXT SAMP SOUR TIMER SAMP TIMER 20e 6 SAMP COUNT 50000 INIT The INIT command arms the trigger system and the system is now waiting for an external trigger Notice that the sample timer can equal the aperture time This example can be modified slightly to use level triggering to trigger at 0 8 V TRIG SOUR INT TRIG LEVEL 0 80 Adding the following command to the level triggering changes would allow 1 000 readings to be taken in pre trigger mode so that 49 000 readings will be taken after the 0 8 V level is exceeded The SAMP COUNT is the overall number of read ings to be taken PRET will subtract from the 50 000 SAMP COUNT PRET 1000 System readings and throughput rates The 34410A and 34411A have excellent programming and data retrieval performance This performance is exhibited in the tables below which are straight from the data sheet There are three paths described
30. rnal or Level Trigger an vam yl P uii i ii ii Aten very PT ri W le Trigger Delay 2 seconds Figure 6 Using an external trigger and a delay to synchronize sampling Borrowing from the earlier battery discharging example an external trigger or level trigger 34411A only can begin the process of making any measurement or waveform capture Simultaneous measurements with multiple DMMs In automotive and aerospace applications with mechanical electrical components it is common to make simultaneous measurements of multiple sensors When you are using switches scanning high voltage signals at high speeds is difficult without attenuation especially when you are using FET switches It is also diffi cult to scan signals that have drastically different voltage levels or different measurement functions at high speeds In these situations you can connect multiple DMMs directly to sensors with all external trigger inputs in parallel to a single trigger event The 34410A and 34411A use hardware coupling to connect external trigger inputs to the measurement engine Trigger latency or jitter is less than 1 us so multiple 34411A DMMs running at 50 k samples s can begin sampling at virtually the same time With each 34411A s reading storage at 1 million readings up to 20 seconds of data can be captured in parallel Using four 34411A DMMs gives an effective sample rate of 200 k samples s an
31. s illustrated in the example where we discussed precision DC measurements of pulses There are many reasons for delaying a measurement You may need to wait for the signal to settle as is typical when you are measuring large resis tances in the presence of stray capacitance In the ballast application we discussed earlier a delay is needed to make the instrument wait until after the initial high voltage discharge has taken place so the quies cent AC voltage level can be measured Trigger Interval Interval Interval Trigger Sample 1 Delay Sample 2 Sample 3 Figure 5 Using a precision timer to sample signals Both the 34410A and 34411A have a hardware coupled external trigger input A delay can be inserted between the external event and the start of any measurement This delay can be zero and the measurement engine starts its measurement in less than 1 us from the external trigger DC measurement The delay can also be up to 3600 seconds with 20 us resolution Both the 34410A and 34411A have a precision sample timer with very little jitter lt 100 ns An external trigger event can start a single measurement or a burst of measurements spaced by the sample timer Figure 5 illustrates the concept of a separate trigger delay and sample intervals Sample intervals can be as low at 100 us for the 34410A and 20 us for the 34411A rent Na Ay S Exte
32. t AutoIP DMM can assign its own IP address or manual IP assignment Once you know the IP address you simply enter that into the Web browser s URL Up to three Web browsers can be simultaneously connected Here are some of the key capabilities provided in the 34410A 34411A Web server e Extends ease of use by showing all parameters at once e Visual aid in developing external programs ES Agilent Technologies foe Digit Multimeter Another web enabled instrument from Agilent Technologies ON Save ony Monitor DMM __ Control DMM __ Dmm Overiew Store RecallState __Commands _ G Allow Full Control Monitor MM oS O Z 0 115 30 MOHM Configuration A Control DMM amp System Status a StatMeas StopMeas ViewData _ Prriot Display Measurement Settings Trigger Settings Page Function Offset Compensation 4w Ohms z Con on Range Auto zl Integration time Resolution 1 PLC lt 3 0E 07 x Range zl Null I Enable Null Null Value Math Functions I Enable Math Trigger Slope C Pos Neg Trigger Source External z Trigger Count 10 F Infinite Trigger Delay sec I7 Auto Sample Count 1 Sample Interval sec 9 Auto VM Complete Slope C Pos Neg oK Close ji e Cut and paste readings into your
33. tain by giving you greater choice in measurements connectivity and programming Utilizing these advantages your team has more time to focus on what matters most the performance reliability and delivery of your product www agilent com find open www agilent com For more information on Agilent Technologies products applications or services please contact your local Agilent office The complete list is available at www agilent com find contactus Phone or Fax United States tel 800 829 4444 fax 800 829 4433 Canada tel 877 894 4414 fax 800 746 4866 China tel 800 810 0189 fax 800 820 2816 Europe tel 31 20 547 2111 Japan tel 81 426 56 7832 fax 81 426 56 7840 Korea tel 080 769 0800 fax 080 769 0900 Latin America tel 305 269 7500 Taiwan tel 0800 047 866 fax 0800 286 331 Other Asia Pacific Countries tel 65 6375 8100 fax 65 6755 0042 Email tm_ap agilent com Contacts revised 09 26 05 Product specifications and descriptions in this document subject to change without notice Agilent Technologies Inc 2006 Printed in the USA August 2 2006 5989 4039EN Agilent Technologies
Download Pdf Manuals
Related Search