Simpson 260® Series 8P Volt-Ohm-Milliammeters
Contents
1. Simpson 260 Series 8P Volt Ohm Milliammeters INSTRUCTION MANUAL About this Manual To the best of our knowledge and at the time written the information contained in this document is technically correct and the procedures accurate and adequate to operate this instrument in compliance with its original advertised specifications Notes and Safety Information This Operator s Manual contains warning headings which alert the user to check for hazardous conditions These appear throughout this manual where applicable and are defined below To ensure the safety of operating performance of this in strument these instructions must be adhered to N Warning refer to accompanying documents AN Caution risk of electric shock This instrument is designed to prevent accidental shock to the operator when properly used However no engineering design can render safe an instrument whick is used carelessly Therefore this manual must be read carefully and com pletely before making any measurements Failure to follow directions can result in serious or fatal accident Shock Hazard As defined in American National Standard C39 5 Safety Re quirements for Electrical and Electronic Measuring and Controlling Instrumenta tion a shock hazard shall be considered to exist at any part involving a potential in excess of 30 volts RMS sine wave or 42 4 volts DC or peak and where a leakage current from that part to ground exceeds 0 5 millia2. 48 long 00043 each with combination probe tip and removable rubber sleeved alligator clip 1 1 5 Volt D Cell NEDA 13F pe 9 0 volt Cell NEDA 1604A 2 1Amp 250V Fuse Littlefuse Type 312001 1 2A 600V Fuse Littlefuse Type BLS or Bussman Type BBS 1 Operator s Manual 6 114339 Batteries are standard items replaceable from local retail stores 10 Table 1 3 Additional Accessories Description Catalog No Deluxe Case 00812 Leatherette Ever Redy Hard Case Drop Front 00805 Model 150 2 Amp Clamp 00545 Model 151 2 Line Splitter 00544 1 13 Accessory AC High Voltage Probe The 10 000 volts AC accessory probe is similar to the high voltage DC probes with the following exceptions The AC high voltage probe is designed to extend the 260 8P AC voltage range The probe can be used with the Simpson 260 8P 10 volt AC range NOTE Instructions are furnished with each high voltage probe 1 14 Amp Clamp Model 150 2 The Simpson Amp Clamp Model 150 2 allows AC current measurements with out breaking the circuit under test The Amp Clamp works as a transformer con taining a split core for accommodating the conductor which carries the current being measured The current carrying conductor becomes the transformer pri mary and a coil in the Amp Clamp serves as the secondary winding The Amp Clamp output voltage is proportional to the current measured and can be applied to the 260 8P as an AC voltage The Amp Clamp has a range select
3. zero setting by subsequent changes in temperature hu midity vibration and other environmental conditions Reset Button The white button to the right of the output jack is the reset button of the overload protection circuit OPERATION 4 1 Multifunction instruments VOMs such as the 260 8P are intended as general purpose measuring Instruments for use in low power circuitry Such as found in consumer appliances TV and radio receivers and in general laboratory applica tions Their use is not recommended in high voltage high power circuitry where operator errors and inadequate personal protective measures could result in serious injury from arcing or explosion Such circuitry is found in industrial or commercial applications such as induction r f heaters and broadcast transmit ters power substations and distribution centers X ray equipment large motor controls etc Working in the high voltage section of such equipment requires single function often specially designed instruments used by trained personnel who adopt appropriate protective equipment and procedures This section of the manual contains information required to use and operate the 260 8P in a safe and proper manner Safety Precautions The following precautions are suggestions and reminders of commonly recog nized safe practices to be adopted and specific hazards to be avoided and are not implied to be sufficient to safeguard untrained personnel in all circu
4. AC position and test leads connected to common and 1000V jack Do not touch the Instrument or test leads while the power is on in the circuit being measured Before proceeding with the following steps review the Safety Precautions in Paragraph 4 2 a Set the function switch at AC Volts Only position Figure 4 8 NOTE The meter will not indicate if the switch is incorrectly set to a DC position b Setthe range switch at the 250V 500V 1000V position c Plug the black test lead into the COM MON jack and the red test lead into the 1000V jack d Be sure power is off in the circuit be ing measured and that all its capaci tors have been discharged e Connect the test leads across the cir cuit voltage to be measured with the black lead to the grounded side f Turn on the power in circuit being mea sured g Read the voltage on the red scale marked AC Use the 0 10 figures and Figure 4 8 Jacks and Switch i Positions for Measuring multiply by 100 AC Voltage 0 1000V Range Output Voltage Measurement Certain situations necessitatethe measuring of the AC component of an Output Voltage where both AC and DC voltage levels exist This occurs primarily in amplifier circuits The 260 8P has a 0 1 mfd 400 volt capacitor in series with the OUTPUT jack The capacitor blocks the DC component of the current in the test circuit but
5. BBS 2A 600V A Littlefuse Type BLS 2A 600V fuse may be used as a substitute replace ment NOTES If the 260 8P fails to indicate a reading the 1 Amp or 2 Amp fuse may be burned out Refer to paragraph 5 4 for fuse replacement Use only the specified fuse type The 0 10A range is not fused The shunt connects directly to the 10A and 10A jacks The relay fuse and diodes will prevent serious damage to the Instrument in most cases of accidental overload However no overload protection system is com pletely foolproof and misapplication on high voltage circuits can damage the Instrument Exercise care and caution to protect both the user and the Instrument Internal Batteries There are two batteries in the ohmmeter circuits a NEDA 13F size D cell that furnishes 1 5 volts for the R X 1 and R X 100 ranges and a NEDA 1604A alkaline battery that furnishes 9 volts for the R X 10 000 range and overload circuit The 1 5 volt D cell is held in place with two spring clips which also serve as battery contacts The polarity symbols for the D cell are marked near the battery contacts The 9 volt battery is held in place with a spring clip but contact is made with a separate connector that is polarized Always observe correct polarity when re placing the 1 5 volt D cell The 9 volt battery must be installed and tested before the Instrument is ready for use Perform the overload test described in Paragraph 1 4 to ensure proper over load circuit
6. The following paragraphs of this section describe battery replacement fuse re placement and preventive maintenance procedures for the 260 Inspection The user is protected from electrical shock by the insulation of the 260 and its test leads Frequently examine them for any insulation damage such as cracks cuts chips burns or deterioration that expose internal metal parts or reduce the spac ing between such metal parts and hand contact by the operator Make certain that the battery compartment cover is securely fastened in place before the Instrument is used Do not permit an instrument with a broken meter glass to be used Whenever the battery compartment cover is removed for any reason check that the proper fuses are being used Battery Replacement a Two batteries are used inside the case to supply power for resistance mea surements One is a 1 5 volt D cell and the other is a 9 volt battery When it is no longer possible to adjust the pointer to zero for the R X 1 and R X 100 ranges refer to ZERO OHMS ADJUSTMENT paragraph 4 21 replace the 1 5 volt cell When it is no longer possible to adjust the pointer to zero on the R X 10 000 range replace the 9 volt battery b Recommended replacement batteries are 1 5V D cell NEDA 13F Duracell MN or Eveready No 95 9V battery NEDA 1604A Duracell MN1604 or Eveready 522 c To install or replace a battery de energize and disconnect test leads from the Instrument then remove
7. allows the AC or desired component to pass on to the indicating instrument circuit The blocking capacitor may alter the AC response at low fre quencies but is usually ignored at audio frequencies Figure 4 9 A Do not connect the OUTPUT jack to a circuit in which the DC voltage component exceeds 350V Before proceeding with the following steps review the Safety Precautions in Paragraph 4 1 a Set the function switch at AC Volts Only position Figure 4 10 b Plug the black test lead into the COMMON jack and the red test lead into the OUTPUT jack c Set the range switch at one of the range positions marked 2 5V 10V 25V 50V or 250V d Connect the test leads across the circuit being measured with the black test lead to the grounded side 21 OUTPUT RANGES 2 5 VAC RANGE 10VAC RANGE 5 50 VAC RANGE 250 VAC RANGE 100Hz 1KHz 10KHz 100KHz 1MHz FREQUENCY Figure 4 9 Frequency Response Output Ranges Figure 4 10 Jacks and Switch Positions for Output Measurements e Turn on the power in the test circuit Read the output voltage on the appropri ate AC voltage scale For the 0 2 5V range read the value directly on the scale marked 2 5V AC For the 10V 25V 50V or 250V ranges use the red scale marked AC and read the black figures immediately above the scale 4 8 Decibel Measurement 20 To 50 dB Some indus
8. been subject to misuse neg ligence or accident incorrect wiring by others or installation or use not in accord with instructions furnished by the manufacturer 2 NOTES Contents INTRODUCTION ua arena 1 1 General Description iriiria a nn 1 2 Overload Protection n0nerennnnenenannnenannenennnenenannnn vannet 1 37 Internal Batteries coomociniiida een lass 1 4 Overload Circuit Test nnrenevanenanannennnnnena vanana nannenennnene 1 5 Pritteds Circuit wussten annehmen 1 67 Phenolic Case 54451144 a eel Soest at se A 1 7 Adjust A Vue Handle 00 2 cece eeeeeceecesceeeeneeceseseeeesenseeeeeeeseneneneeeeneees 1 8 Testi cuca 19 Technical Datura tad 1 10 Definition of Accuracy ccooonccconcccnnoccnnnoncnonannncnanannnnonnnnnnn cnn narnnnnnnn cenamos 1 11 Safety Considerations rrrrnrnnonvnnnvrronvnnnnrnrrvrnenrnrrnrnnnvenenrenenrnnnnenen 1 12 Audio Alarm zittern ren ee A 1 13 Accessory AC High Voltage Probe etmnrennenanne 1 14 Amp Clamp Model 150 2 unnsusssennssnnsnnennnnnnnnnnnnnnnnnnnennnnennnnnn INSTAELATION raste ae ee bank 2 1 Unpacking and Inspection ooooconoccc noncccnnnanonanancnnoracnnnnrnnnnnrn nn nrn nn 22 Walras a it 2 3 Shippinguanasiarutnagstunuanee naa ee 2 4 Power Source Requirements usnerssensneensnnnnnnensnnnnnnennnnnnnnnnnnnnn nn 2 9 Operating Position kent etree dts een CO
9. Accuracy The voltage and current accuracy of this Instrument is commonly expressed as a percent of full scale This should not be confused with accuracy of reading indi cation For example 2 of full scale on the 10 volt range allows an error of 0 20V at any point on the dial This means that at full scale the accuracy reading would be 2 but at half scale it would be 4 Therefore it is advantageous to select a range which gives an indication as near as possible to full scale 1 11 Safety Considerations This Operator s Manual contains special caution and warning symbols which alert the user to hazardous operating and service conditions These symbols appear throughout this publication where applicable and are defined on the inside front cover of this manual under NOTES AND SAFETY INFORMATION Please adhere to these instructions to ensure the safety of operating and servic ing personnel and to retain the operating conditions of the Instrument 1 12 Audio Alarm The 260 8P Audio Alarm is a transducer which will emit an audible sound when the operator of the Instrument intends to quickly determine the continuity of a circuit NOTE Not protected by Electronic Overload Protection System A Do not make Circuit Continuity Tests with electrical power ON Turn OFF all electrical power Table 1 2 ltems and Accessories Furnished with This Instrument Quantity Description Number 1 Test Lead Set one red and one black
10. NTROLS JACKS AND INDICATORS rrrvnrrnnnvvvnrrrnnrrvnnrrrsrrnnnrene 3 1 Front Panel Description eswnrernenatennanennanaeenaeneneennanenua OPERATION 50 Na o 4 1 Safety Precautions unnneessenssnnnsnennnnennnnnnnonnnnnnnnnnnnennnnnnnnnnnnnnnnnnann 4 2 Polarity Reversing sesia aea aaae aa iaaa aiaa 4 3 Measurement of Unknown Voltage or Current 4 4 Testibeads unimarc 4 5 DC Voltage Measurement rrrnnrnnnvrnenvnnnvrnenvnnnvnnenrnennenenrnervrnenrnrnrenen 4 5 1 DC Voltage Measurement 0 250 mV Range 4 5 2 DC Voltage Measurement 0 1V Range 4 5 3 DC Voltage Measurement 0 2 5 Through 0 250V Range 4 5 4 DC Voltage Measurement 0 500V Range 4 5 5 DC Voltage Measurement 0 1000V Range 4 6 AC Voltage Measurement rrnnnvrnnnvnnnvvnnnvnnnvnnnnrnrnvnnennnennnr 4 6 1 AC Voltage Measurement 0 2 5 Thru 0 250V Range 4 6 2 AC Voltage Measurement 0 500V Range seeen 4 6 3 AC Voltage Measurement 0 1000V Range e 4 7 Output Voltage Measurement stenenneneennnenenenai 4 8 Decibel Measurement 20 To 50 dB nmerssnnnersnnnensnnnernennn nenn 4 9 Direct Current Measurement rrnnnnnnonvnnnvrnnnvnnnvnnrnrnnnvnnenrnrsvnnenrnrnnnne 4 9 1 Direct Current Measurement 0 50uA Range secsec 4 9 2 Direct Current Measurement 0 1mA Through 0 500mA Range 23 4 9 3 Direct Current Measurement 0 10A Range unnnensenneensensenneenn
11. ROLS JACKS AND INDICATORS All operating and adjustment controls jacks and indicators for the Simpson 260 8P are illustrated in this section along with a list Table 3 1 describing their function Become familiar with each item before operating the Instrument 3 1 Front Panel Description The front panel controls jacks and indicators as described in Table 3 1 are depicted in Figure 3 1 Table 3 1 Controls Jacks and Indicators 1 Front Panel The 260 8P Volt Ohm Milliammeter is a large easy to read 4 1 4 indicating Instrument Below the Instrument are four controls and eight circuit jacks Switch positions and circuit jacks are marked in white characters for easy reading 2 Range Switch 12 positions May be rotated 360 in either direction to select any of the five AC and DC voltages four DC cur rents and three resistance ranges 12 3 3 104 350VDC ACNOLTS Max ONLY so panies P 280 WW ZERO OHMS FIGURE 3 1 Front Panel Controls Jacks Function Switch Zero Ohms Circuit Jacks Pointer Adjust For Zero and Indicators The function switch has four positions Audio 4 DC DC and AC Volts only To measure DC current or voltage set the function switch at the DC or DC position depend ing on the polarity of the signal applied across the test leads To measure AC voltage s
12. THE INSTRUCTIONS AND PRECAUTIONS IN THE OPERATOR S MANUAL FAILURE TO FOLLOW INSTRUC TIONS CAN RESULT IN A SERIOUS OR FATAL INJURY FETY TIPS DO NOT ATTEMPT ANY MEASUREMENTS UNLESS TRAINED QUALIFIED AND AUTHORIZED TO DO SO 2 DO NOT CONNECT TO ANY CIRCUIT WHERE THE VOLTAGE WITH RESPECT TO EARTH GROUND MAY EXCEED 1000 VOLTS 3 WHENEVER MAKING MEASUREMENTS WITH THIS INSTRUMENT TURN OFF CIRCUIT POWER AND DISCHARGE ANY CAPACITANCE IN THE CIR CUIT BEFORE CONNECTING OR DISCONNECTING TEST LEADS OR CHANG ING SWITCH SETTINGS B DOUBLE CHECK FOR CORRECT SWITCH SETTINGS AND TEST LEAD CONNEC TIONS BEFORE APPLYING POWER DO NOT TOUCH THE INSTRUMENT TEST LEADS OR CIRCUIT WHILE POWER N ISO D DO NOT USE ANY INSTRUMENT OR TEST LEADS THAT ARE DAMAGED CON TAMINATED DETERIORATED MOIST OR WHICH HAVE MISSING PARTS 4 READ THE OPERATOR S MANUAL FOR ADDITIONAL PRECAUTIONS AND IN STRUCTIONS MADE IN U SA BY SIMPSON ELECTRIC COMPANY ELGIN ILLINOIS SD Figure 5 1 Battery and Fuse Compartment 28 29 NOTES 30 NOTES 31 SIMPSON ELECTRIC COMPANY 853 Dundee Avenue Elgin IL 60120 3090 847 697 2260 FAX 847 697 2272 Printed in U S A Part No 06 114339 Edition 8 12 01 Visit us on the web at www simpsonelectric com
13. Turn off power to the circuit to be measured and discharge any ca pacitors e Connect the test leads across the circuit voltage to be measured with the black lead to the grounded side f For the 2 5V range read the value directly on the scale marked 2 5V AC For the 10V 25V 50V and 250V ranges read the red scale marked AC and use the black fig ure immediately above the scale PERCENT RELATIVE ERROR N O jer acvours On av IM av en Bl za common 4 E O ALTERMINALS1VMAX 1 Ly Figure 4 6 Jacks and Switch Positions for Measuring AC Voltages 0 2 5 through 0 250V Ranges 19 Figure 3 1 Frc 4 6 2 AC Voltage Measurement 0 500V Range A Do not attempt any voltage measurement which may exceed 1000 volts or the circuit to ground voltage of the Instrument 1000 volts maximum Be sure that the range switch is set to the 250V 500V 1000V range function switch to AC Volts Only position and test leads connected to common and 500V jack Do not touch the Instrument or test leads while the power is on the circuit being measured Use extreme care when working in high voltage circuits Do not handle the Instru ment or test leads while the circuit being measured is energized OBSERVE ALL SAFETY PRECAUTIONS in paragraph 4 1 and in the instruction manual for the equipment being tested Before proceeding with the
14. ange is not internally fused in the 260 8P common When using the 10A range never disconnect a test lead from a jack or from the circuit while the circuit is energized Doing so may damage the test jacks or leads and the arcing may be hazardous to the operator Turn off circuit power and wait for the meter reading to drop to zero The polarity reversing feature of the function switch does not operate on the 0 10A range If polarity is found to be incorrect turn off circuit power wait for the meter indication to reach zero and then interchange test lead connections to the circuit 24 4 10 Resistance Measurements A Voltage applied to a resistance range will cause reading errors if low and dam age the Instrument if high When making in circuit measurements make certain that the circuit is completely de energized before making connections to it When making in circuit measurements circuit paths in parallel with the resis tance being measured may cause reading errors Check circuit diagrams for the presence of such components before assuming that the reading obtained is correct When resistance is measured the batteries furnish power for the circuit Since batteries are subject to variation in voltage and internal resistance the Instru ment must be adjusted to zero before measuring a resistance as follows a Turn range switch t
15. ble for greater accuracy since the Instrument is calibrated in this position 1 8 Test Leads Each Instrument is furnished with one pair Catalog Number 00043 of probe type test leads one red and one black each 48 inches long for all applications of the Instrument These test leads have elbow prods on one end to connect the leads to the recessed jacks on the Instrument front panel The probe tips at the opposite end have threaded shoulders to accept the screw on insulated alligator clips furnished with the test leads or the 5000 volt test probe s to extend the Instrument AC or DC voltage range The test leads and the insulated alligator clips are rated for the voltage and current ranges available on the 260 Maximum ratings are 1000V AC or DC or 10 DC amperes These ratings for the test leads must not be exceeded in any application 1 9 Technical Data Table 1 1 Technical Data 1 DC VOLTS Ranges 0 1 2 5 10 25 50 250 500 1000V Sensitivity 20 000 ohms per volt 2 DC MILLIVOLTS Range 0 250mV Sensitivity 20 000 ohms per volt 3 ACVOLTS Ranges 0 2 5 10 25 50 250 500 1000V Sensitivity 5 000 ohms per volt 4 OUTPUT VOLTAGE AC Ranges 0 2 5 10 25 50 250 limited to 350VDC 8 5 DC MICROAMPERES Range 0 50uA Voltage Drop 250mV 6 DC MILLIAMPERES Ranges 0 1 10 100 500 mA Voltage Drop Approx 250 mV 255 mV 300 mV 500 mV 7 DC AMPERES Range 0 10A Voltage Drop Approx 255mV NOTE The 10A range is
16. by an electronic overload protection system The protection is from the usual overloads that would damage the VOM A transistorized circuit senses the voltage drop across the indicating instrument and actuates a relay when the voltage reaches approximately three to four times rated full scale voltage Sens ing of the voltage drop is by means of a bridge network so that overload protec tion is provided regardless of polarity The relay operates at a uniform percent of overload since the indicating instrument circuit is common to all ranges When actuated by an overload the relay contacts which are in the COMMON CIR CUIT latch open until the reset button on the front panel is depressed The reset button is located to the right of the output jack A Due to its sensitivity to overloads the electronic overload protection relay incor porated in the 260 8P is susceptible to electrostatic fields from high potentials or transients either in the circuit being measured or in nearby circuitry Do not assume the relay to be faulty if it trips out without apparent cause It may be indicating a dangerous condition such as excessive circuit to ground floating voltage being applied to the Instrument Avoid loading the Instrument or its test leads until certain that excessive circuit to ground voltage does not exist a A switch that is opened when the relay latches opens the relay circuit and prevents continuous battery drain This condition occurs wh
17. d and the red test lead to the positive side of the circuit Read the voltage on the black scale marked DC and use the figures marked 0 10 Then divide the reading by 10 NOTE For polarity reversing see para graph 4 2 16 7 N Figure 4 1 Jacks and Switch Positions for Measuring DC Voltages 0 through 1V Ranges a Set the function switch at DC Figure 4 2 b Plug the black test lead into the COM MON jack and the red test lead into the jack c Set the range switch at one of the five voltage range positions marked 2 5V 10V 25V 50V or 250V NOTE When in doubt as to the voltage present always use the highest voltage range as a protection to the Instrument If the voltage is within a lower range the switch may be set for the lower range to obtain a more accurate reading Be sure power is off in the circuit being measured and all capacitors discharged d Connect the black test lead to the nega tive side of the circuit being measured and the red test lead to the positive side of the circuit e Turn on the power in the circuit being measured f Read voltage on the black scale 4 5 3 DC Voltage Measurement 0 2 5 Through 0 250V Range so palos 280 My common U Figure 4 2 Jacks and Switch Positions for Measuring DC Voltag
18. e Instrument switches are set properly jacks are con nected properly and that the circuit power is turned off before making connec tions to such circuits The 260 responds to the average value of an AC waveform lt is calibrated in terms of the RMS value of a pure sine wave If the waveform is nonsinusoidal and 18 depending upon its waveform the reading may be higher or lower than the true RMS value of the measured voltage Thus an error may be introduced if the 260 is used to measure a nonsinusoidal waveform Also accuracy is lessened at higher input frequencies Figure 4 5 4 6 1 AC Voltage Measurement 0 2 5 Thru 0 250V Range Before proceeding with the following steps review the Safety Precautions in Paragraph 4 1 a Set the function switch at AC Volts Only position Figure 4 6 NOTE The meter will not indicate if AC VOLTAGE RANGES the switch is incorrectly set to a 2 5 VAC RANGE DC position IS VAC RANGE crane b Setthe range switch at one of the AO E E R 500 VAC RANGE 1000 VAC RANGE five voltage range positions marked 2 5V 10V 50V or 250V When in doubt as to actual volt age present always use the highest voltage range as a pro tection to the Instrument If the voltage is within a lower range the switch may be set for the lower range to obtain a more ac curate reading c Plug the black test lead into the ae SR EE ME Serre the red test Figure 4 5 Frequency Response ar AC Voltage Ranges d
19. eans to reverse polarity of the inter nal battery to facilitate testing semiconductor devices The DC and DC posi tions transpose internal connections to the COMMON and jacks and therefore can also be used to reverse polarity of external voltages and currents connected to these jacks only Because polarity reversing momentarily interrupts the cir cuit it should not be done while measuring current or voltage without first turning off the circuit power When making measurements on the 50uA 250mV 1 volt or 10 amp range polarity can be corrected only by reversing the test leads Measurement of Unknown Voltage or Current Sometimes the approximate voltage or current to be measured is known and the correct range may easily be selected It is often the case however particularly when working upon faulty equipment when the voltage or current is either un known or may be much higher than normal and anticipated Whenever working upon unfamiliar or unknown equipment always begin a measurement using the highest range available on the Instrument Once it is determined that the voltage is within the limits of a lower range change to the lower range 15 4 4 Test Leads Test leads are provided with accessory screw on alligator clips which may be attached to the probe tips Eliminating the need to hand hold test prods to a circuit for extended periods the test clips also reduce hand proximity to a high voltage circuit while energized Circuit
20. en the reset but ton has been pressed so that the VOM is operational the protection circuit draws less than the shelf life drain of the battery b Since the 9V battery is used for both the R X 10 000V range and the protec tion circuit the VOM is designed to allow the protection circuit to function normally as long as the R X 10 000V range can be set to zero and an Alka line Battery is used c The 1 and 2 Amp fuses in the input circuit adds protection to the relay con 6 1 3 1 4 tacts Some overload conditions may cause the fuses to burn out as well as open the relay contacts d When an overload of sufficient magnitude is applied to the VOM the reset button will pop up approximately 3 16 above the surface of the panel To reset the VOM for normal operation first remove the overload and depress the button If the overload remains connected to the Instrument resetting the overload protection reset button will not connect the VOM input circuit In addition to the overload protection circuit two diodes protect the indicating instrument circuit These diodes limit the current through the coil in case of over load Fuses Basic Overload protection is provided by a small inexpensive and easily obtainable 3 AG type 1 Amp quick blow fuse This fuse is rated to interrupt circuit voltages up to 250 volts A supplemental high energy fuse is provided for addi tional protection from severe overloads This fuse is the Bussman Type
21. er exceed the circuit to ground voltage of the instrument 1000V Max Table 1 1 Item 16 Always connect the instrument in se ries with the ground side of the cir oe k cuit SN OR Y In all direct current measurements make certain the power to the circuit Figure 4 11 Jacks and Switch being tested has been turned off be Positions for Measuring Decibels fore connecting and disconnecting test leads or restoring circuit conti nuity Direct Current Measurement 0 50uA Range Set the function switch at DC Plug the black test lead into the COMMON jack and the red test lead into the 50uAMPS 250mV jack Set the range switch at 50UAMPS dual position with 50V Open the ground side of the circuit in which the current is being measured Connect the VOM in series with the circuit Connect the red test lead to the positive side and the black test lead to the negative side Read the current on the black DC scale Use the 0 50 figures to read directly in microamperes NOTE For polarity reversing see paragraph 4 2 4 9 2 Direct Current Measurement 0 1mA Through 0 500mA Range Set the function switch at DC Figure 4 12 Plug the black test lead into the COMMON jack and the red test lead into the jack Set the range switch at one of the four range positions marked 1 mA 10 mA 100 mA or 500 mA 23 d Open the grounded side of the ci
22. es 0 250V Range marked DC For the 2 5V range use the 0 250 figures and divide by 100 For the 10V 50V and 250V ranged read the figures directly For the 25V range use the 0 250 figures and divide by 10 NOTE Turn off power to the circuit and wait until the meter indicates zero before disconnecting the test leads AN Use extreme care when working with high voltage circuits Do not touch the Instrument or test leads while power is on in the circuit being measured Before proceeding with the following steps review the Safety Precautions in Paragraph 4 1 a Set the function switch at DC Figure 4 3 b Setthe range switch at the 250V 550V 1000V Position c Plug the black test lead into the COM MON jack and the red test lead into the 500V jack d Be sure power is off in the circuit being measured and all capacitors dis 17 4 5 4 DC Voltage Measurement 0 500V Range Figure 4 3 Jacks and Switch Positions for Measuring DC Voltages 0 500V Range charged Connect the black test lead to the negative side of the circuit being measured and the red test lead to the positive side of the circuit e Turn on power in circuit being measured Read the voltage using the 0 50 figures on the black scale marked DC Multiple the reading by 10 NOTE Turn off power to the circuit and wait until the meter i
23. et the function switch to the AC position For resistance measurement the switch may be set in either the DC or DC position The polarity of the internal ohmmeter battery voltage will be as marked at the jacks when the switch is in the DC position and reversed in the DC position This control is used to compensate for variation in the volt age of the internal batteries when making resistance mea surements There are eight jacks on the front panel marked with the functions they represent These jacks provide the electri cal connections to the test leads The COMMON jack is used in conjunction with the black test lead as the refer ence point for the measurement of all the functions with the exception of the 10 A range Refer to Section 4 for details With the Volt Ohm Milliammeter in an operating position check that the pointer indicates zero at the left end of the scale when there is no input If pointer is off zero adjust the screw located in the cover below the center of the dial Use a small screwdriver to turn the screw slowly clockwise or counterclockwise until the pointer is exactly over the zero mark at the left end of the scale With the indicating pointer 13 7 4 set on the zero mark reverse the direction of rotation of the zero adjuster slightly to introduce mechanical freedom or play but insufficient to disturb the position of the indicat ing pointer This procedure will avoid disturbances to the
24. following steps review the Safety Precautions in Paragraph 4 2 a Set the function switch at AC Volts Only position Figure 4 7 NOTE The meter will not indicate if the switch is incorrectly set to a DC po sition b Set the range switch at the 250V 500V 1000V position c Plug the black test lead into the COMMON jack and the red test lead into the 500V jack d Be sure the power is off in the circuit being measured and that all its ca pacitors have been discharged e Connect the test leads across the circuit voltage to be measured with the black lead to the grounded side if any Turn on the power in the circuit be ing Measured Figure 4 7 Jacks and Switch Positions for Measuring AC Voltage g Read the voltage on the red scale 0 500V Range marked AC Use the 0 50 figures and multiply by 10 4 6 3 AC Voltage Measurement 0 1000V Range Use extreme care when working in high voltage circuits Do not handle the Instru ment or test leads while the circuit being measured is energized OBSERVE ALL SAFETY PRECAUTIONS in paragraph 4 1 and in the instruction manual for the equipment being tested Do not attempt any voltage measurement which may exceed 1000 volts or the circuit to ground voltage of the Instrument 1000 volts maximum 20 4 7 Be sure that the range switch is set to the 250V 500V 1000V range function switch to
25. ge of the test leads or Instruments i Do not change switch settings or test lead connections while the circuit is energized A mistake could result in damage to the Instrument and personal injury j Locate all voltage sources and accessible current paths before making con nections to circuitry High voltages may appear unexpectedly or in unex pected locations in faulty equipment An open bleeder resistor for example may result in a capacitor retaining a dangerous charge k Make certain that the equipment being worked upon is properly grounded and fuses are of the proper type and rating Double check switch positions and jack connections before applying power to the Instrument m Remain alert for low voltage circuits which may be floating at high voltage with respect to earth ground and for composite voltages AC DC such as are found in r f amplifiers The floating voltage or composite voltage must not exceed the Instruments rated maximum circuit to ground voltage n Do not make electrical measurements where the air may contain explosive concentrations of gas or dust such as in mines grain elevators gasoline stations or in the presence of charging batteries until determined to be safe by qualified personnel Note that even metallic dusts can be explosive o No General Purpose VOM is to be used to make electrical measurements on blasting circuits or blasting caps Polarity Reversing The function switch provides a convenient m
26. miconductor material is germanium check the ratings of the device and refer to Table 1 1 item 8 NOTE The resistance of diodes will measure differently from one resistance range to another on the VOM with the function switch in a given position For example a diode which measures 80 ohms on the R X 1 range may mea sure 300 ohms on the R X 100 range The difference in values is a result of the diode characteristics and is not indicative of any fault in the VOM 4 13 4 13 Continuity Tests ees A Turn off all power to the circuit under test before proceeding any further a Set the FUNCTION switch to the 4 Insert the black test lead into the COM MON and the red test lead into the jacks Figure 4 14 Touching the test lead probe tips to gether should produce an audible sound To test for continuity probe the circuit or component in question An audible sound indicates continuity The higher the circuit s resistance the lower the sound level The lower the circuit s resistance the higher the sound level Refer to Paragraph 4 12 Figure 4 13 ES o Sipe ZERO OHNS Rx 100 Rx 10 000 6 KS V ALLTERMINALSIV MAX L AH Figure 4 14 Jacks and Switch Positions for Continuity Tests for measurements of circuit resistance if any that exists 26 5 5 1 5 2 5 3 OPERATOR MAINTENANCE
27. mpere when mea sured with an appropriate measuring instrument defined in Section 11 6 1 of ANSI C 39 5 Technical Assistance SIMPSON ELECTRIC COMPANY offers assistance Monday through Friday 7 30 am to 5 00 pm Central Time by contacting Technical Support or Customer Service at 847 697 2260 Internet http www simpsonelectric com Warranty and Returns SIMPSON ELECTRIC COMPANY warrants each instrument and other articles manufactured by it to be free from defects in material and workmanship under normal use and service its obligation under this warranty being limited to making good at its factory or other article of equipment which shall within one 1 year after delivery of such instrument or other article of equipment to the original pur chaser be returned intact to it or to one of its authorized service centers with transportation charges prepaid and which its examination shall disclose to its satisfaction to have been thus defective this warranty being expressly in lieu of all other warranties expressed or implied and of all other obligations or liabilities on its part and SIMPSON ELECTRIC COMPANY neither assumes nor authorizes any other persons to assume for it any other liability in connection with the sales of its products This warranty shall not apply to any instrument or other article of equipment which shall have been repaired or altered outside the SIMPSON ELECTRIC COMPANY factory or authorized service centers nor which has
28. mstances Neither is this manual a substitute for technical manuals covering the equipment in which measurements are to be made Always refer to the equipment manual and its specific warnings and instructions and observe them as well as those contained herein a The 260 8P should only be used by personnel qualified to recognize shock hazards and trained in the safety precautions required to avoid possible injury b Do not connect any terminal of this Instrument to a circuit point at which a voltage exceeding 1000V AC or DC may exist with respect to earth ground Ref Table 1 1 Item 16 c Turn off power and discharge any capacitors in the circuit to be measured before connecting to or disconnecting from it d Before using this Instrument check accessories if any and test leads for missing damaged deteriorated or otherwise faulty insulating parts Do not use or permit the use of equipment with faulty insulation until it has been properly repaired e Always wear safety glasses when working with electrical circuitry 14 4 2 4 3 f Do not work alone on high voltage circuits Make certain that someone ca pable of giving aid is nearby and alert g Do not handle the Instrument its test leads or the circuitry while high voltage is being applied h Hands shoes floor and workbench must be dry Avoid making measure ments under humid damp or other environmental conditions that could effect the dielectric withstanding volta
29. ndicates zero before disconnecting the test leads mh 4 5 5 DC Voltage Measurement 0 1000V Range A Use extreme care when working with high voltage circuits Do not touch the Instrument or test leads while power is on in the circuit being measured Before proceeding with the following steps review the Safety Precautions in Paragraph 4 1 a Set the function switch at DC Figure 4 4 7 m b Setthe range switch at the 250V 500V 1000V Position c Plug the black test lead into the COM MON jack and the red test lead into the 1000V jack d Be sure power is off in the circuit be ing measured and all capacitors dis charged Connect the black test lead to the negative side of the circuit be ing measured and the red test lead to the positive side of the circuit e Turn on power in circuit being mea sured f Read the voltage using the 0 10 fig ures on the black scale marked DC KS Multiple the reading by 100 NOTE Turn off power to the circuit and wait Figure 4 4 Jacks and Switch until the meter indicates zero before Positions for Measuring DC disconnecting the test leads Voltages 0 1000V Range 5 4 6 AC Voltage Measurement A Branch and distribution circuits 120 240 480V etc can deliver dangerous ex plosive power momentarily into a short circuit before the fuse breaker opens the circuit Make certain that th
30. neutralize the corrosive action When Instrument is not in use rotate the function switch to the DC position Avoid prolonged exposure or usage in areas which are subject to tempera ture and humidity extremes vibration or mechanical shock dust or corrosive fumes or strong electrical or electromagnetic interferences Verify Instrument accuracy by performing operational checks using known accurate stable sources If proper calibration equipment is not available contact the nearest Authorized Service Center If the Instrument has not been used for 30 days check the batteries for leakage and replace if necessary It is recommended that the Instrument be returned annually to the nearest Authorized Service Center or to the factory for an overall check adjustment and calibration When the Instrument is not in use store it in a room free from temperature extremes dust corrosive fumes and mechanical vibration or shock If stor age time is expected to exceed 30 days remove batteries SPARE 1A FUSE 2A FUSE 9V BATTERY WARNING TO AVOID ELECTRIC SHOCK MAKE CERTAIN THAT THE TEST LEADS ARE DISCON NECTED FROM ANY CIRCUITS BEFORE REMOVING THE BATTERY ANO FUSE COM PARTMENT COVER DO NOT ATTEMPT ANY FURTHER DISASSEMBLY NO OTHER USER SERVICEABLE PARTS INSIDE REFER SERVICING TO QUALIFIED PERSONNEL 1A FUSE CARELESSNESS AND MISUSE OF THIS INSTRUMENT CAN BE DANGEROUS BEFORE CONNECTING THIS INSTRUMENT CAREFULLY READ
31. nnne 24 4 10 Resistance Measurement nnseseneneennnenennnnnnennnnnnen ernennen rn 25 4 11 Measuring Resistance nuusmnsnannensnannnnnnnnnnnnnnnnnnsnnnnnnnnn nennen 25 4 12 Resistance Measurement of Semiconductors 25 4 13 Continuity Tests u te 26 OPERATOR MAINTENANCE rorrnnrrrnnnrrnvnnrrsrsrrnrrnnrssssrnnnrnsessrrrsnnnnner 27 5 1 Inspection voca EE EE 27 Battery Replacement rrnnrnnnnnvnornnnnnvnnnnnnnvnvnonnnnnnnnnnnnnnennnnnnnnvnsnennene 27 Fuse Replacement xp 1544 cs eset aan 27 Test Lead Inspection mneannmeenaeneannnanaaanaannaenaa naa 28 N E AE E A 28 1 INTRODUCTION 1 1 1 2 General Description The Simpson Volt Ohm Milliammeter 260 Series 8P hereafter referred to as the 260 or as the Instrument is a rugged accurate compact easy to use Instrument equipped with mirrored dial to eliminate parallax The Instrument can be used to make accurate measurements of AC and DC voltage direct current resistance decibels and Output Voltage The Output Voltage function is used for measuring the AC component of a mixture of AC and DC voltage This occurs primarily in amplifier circuits New Features in the 260 8P are 0 25V AC DC Range Continuity Test Alarm Individual Dual Jacks for the 500V AC DC and 1000V AC DC Ranges Overload Protection All the ranges with exception of 1V 10A 50 pA 250mV 500 1000V AC and DC are protected
32. not internally fused 8 RESISTANCE cios Rx 70 000 0 2 0000 0 200 0000 0 20 MQ 12000 1205000 Range Center Reading Nominal Open Circuit Voltage 125mA 1 25mA 75uA 2 of Full Scale Nominal Short Circuit Current 9 ACCURACY DC Voltage Ranges DC Current 0 50 uA Range Other Ranges AC Voltage Ranges Frequency Response 1 5 of Full Scale 2 of Full Scale 3 of Full Scale Referenced to 100 Hz Figures 4 5 and 4 9 Resistance Ranges RX1 2 5 of Arc R X 100 2 of Arc R X 10 000 2 of Arc 10 DECIBELS Range 20 to 10 dB 8 to 22 dB Reference Level 0 to 30 dB 6 to 36 dB 20 to 50 dB With zero dB power level equal to 1 mW across a 6000 line 11 BATTERIES Voltage 1 5V 9V NEDA No 13F 1604A 12 FUSE F1 1A 250V type 3AG quick acting Littlefuse Type 312001 F2 2A 600V Littlefuse Type BLS or 2A 600V Bussman Type BBS 13 TEST LEADS 1 red 1 black 48 long 14 SIZE 512 x 7 x 3 13 34 x 17 78 x 7 94 cm 15 WEIGHT 3 Ibs 1 359 kg 16 RATED CIRCUIT TO GROUND VOLTAGE 1000V AC DC Max 9 Accuracies specified are for the 260 in a horizontal position Responds to the average value of an AC current and is calibrated to indicate the RMS value of a pure sine wave Per ANSI C39 5 April 1974 The specified voltage with respect to ground which may be safely and continuously applied to the circuit of an Instrument 1 10 Definition of
33. o desired ohms range b Plug the black test lead into the COMMON jack and the red test lead into the jack c Connect the ends of test leads together to short the VOM resistance circuit d Rotate the ZERO OHMS control until pointer indicates zero ohms If pointer cannot be adjusted to zero one or both of the batteries must be replaced For battery replacement refer to Section 5 e Disconnect shorted test leads 4 11 Measuring Resistance a Before measuring resistance in a circuit make sure the power is off to the circuit being tested and all capacitors are discharged Disconnect shunting components from the circuit before measuring its resistance b Set the range switch to one of the resistance range positions as follows Figure 4 13 1 Use R X 1 for resistance readings from 0 to 2000 2 Use R X 100 for resistance readings from 200 to 20 0000 3 Use RX 10 000 for resistance readings above 20 0000 c Set the function switch at either DC or DC position Operation is the same in either position except if there are semiconductors in the circuit See para graph 4 12 Adjust ZERO OHMS control for each resistance range d Observe the reading on the OHMS scale at the top of the dial NOTE The OHMS scale reads from right to left for increasing values of resis tance e Todetermine the actual resistance value multiply the reading by the factor at the switch position K on the OHMS scale equals one thousand 4 12 Resi
34. operation prior to using the Instrument Overload Circuit Test a Setthe range switch to R X 10 000 POSITION and the function switch to DC POSITION b Plug the black test lead into the COMMON jack terminal and touch the other end of the test lead to the 1 volt input terminal The relay reset button should rise indicating that the overload circuit is in working condition NOTE No damage will occur to the 260 8P as a result of this test 7 1 5 Printed Circuit Most of the component parts are mounted on a printed circuit board which simpli fies assembly and maintenance thus extending the useful life of the Instrument 1 6 Phenolic Case The phenolic case is designed with heavy reinforced walls for maximum durabil ity and provides excellent protection for the circuit components The case has an externally accessible battery and fuse compartment Access to the batteries and fuses is obtained by unscrewing a single captivated screw at the bottom of the case and sliding out the compartment cover Rubber plug bumpers on the bottom of the case reduce sliding should the 260 be accidentally pulled by the test leads when the Instrument is on a workbench 1 7 Adjust A Vue Handle A carrying handle is attached to the Instrument case The handle may be used to support the Instrument in a convenient sloping position for easy viewing The case can also be placed in either a vertical or horizontal position The horizontal position is prefera
35. or with six positions Any of the following current ranges can be used with the 260 8P 5 10 25 50 100 or 250 amperes NOTE Instructions are furnished with each Amp Clamp 2 INSTALLATION This section contains information and instructions for the installation and ship ping of the Simpson 260 8P Included are unpacking and inspection procedures warranty shipping power source requirements and operating position 2 1 Unpacking and Inspection Examine the shipping carton for signs of damage If damaged notify the carrier and supplier and do not attempt further use of the Instrument If Instrument ap pears to be in good condition read Operator s Manual in its entirety Become familiar with the Instrument as instructed in the manual then proceed to check the electrical performance as soon as possible Also check that all items listed in Table 1 2 are included with the Instrument After unpacking the Instrument a 1 5V battery and a 9V battery may be found in separate envelopes in the box with the Instrument and the test leads Two alliga tor clips for the test leads are in a polyethylene bag See Section 5 for instructions on how to open the battery compartment and install the batteries 2 2 Warranty The Simpson Electric Company warranty policy is printed on the inside front cover of this manual Read it carefully before requesting any warranty repairs For 11 all assistance including help with the Instrument under warran
36. power must of course be turned off and any charged capacitors discharged before connecting or disconnecting clips to or from the current 4 5 DC Voltage Measurement A Before making voltage measurements review the SAFETY PRECAUTIONS listed in paragraph 4 1 Also when using the 260 as a millivoltmeter take care to pre vent damage to the indicating instrument from excessive voltage 4 5 1 a b c d e DC Voltage Measurement 0 250 mV Range Before using the 250 millivolt range use the 1 0 volt DC range to determine that the voltage measured is not greater than 250 millivolts or 25 volt DC Set the function switch at DC Figure 4 1 Plug the black test lead in the COMMON jack and the red test lead into the 50uAmps 250mV 10A jack Set the range switch at 50 Amps COMMON position with 50V Connect the black test lead to the negative side of the circuit being measured and the red test lead to the positive side of the circuit Read the voltage on the black scale marked DC and use the figures marked 0 250 Read directly in millivolts NOTE For polarity reversing see paragraph 4 2 4 5 2 a b DC Voltage Measurement 0 1V Range Set the function switch at DC Figure 4 1 Plug the black test lead into the COM MON jack and the red test lead into the 1V jack Set the range switch at 1V COMMON position with 10V Connect the black test lead to the nega tive side of the circuit being measure
37. rcuit in which the current is being measured Connect the VOM in series with the circuit Connect the red test lead to the positive side and the black test lead to the negative side e Turn the power on Read the current in milliamperes on the black DC scale For the 1 mA range use the 0 10 figures and divide by 10 For the 10 mA range use the 0 10 figures directly For the 100 mA range use the 0 10 figures and multiply by 10 For the 500 mA range use the 0 50 figures and multiply by 10 f Turn the power off and disconnect the test leads A This range is only intended for measurements in low voltage circuits under 25V DC such as the primary power in vehicles or their accessories 4 9 3 Direct Current Measurement 0 10A Range a Plug the black test lead into the 10A jack and the red test lead into the 10A jack b Setthe range switch at 10 AMPS dual position with 10 mA c Open the grounded side of the circuit in which the current is being mea sured Connect the VOM in series with the circuit connecting the red test lead to the positive side and the black test lead to the negative side NOTE The function switch has no effect on polarity for the 10 AMPS range d Turn the power on Read the current directly on the black DC scale Use the 0 10 figures to read directly in am peres W e Turn the power off and disconnect the test leads Figure 4 12 Jacks and Switch Positions for Measuring Direct Current The 10A r
38. stance Measurement of Semiconductors AN Make sure that the OHMS range being used will not damage any of the semicon ductors refer to Table 1 1 item 8 Section 1 If there is a forward and backward resistance such as in diodes the resistance should be relatively low in one direction for forward polarity and higher in the opposite direction 25 Rotate the function switch between the two DC positions to reverse polarity This will determine if there is a difference between the resistance in the two directions To check a semiconductor in or out of a circuit forward and reverse bias resistance measurements consider the following be fore making the measurement a d The polarity of the internal ohmmeter battery voltage will be as marked at the jacks when the switch is in the DC position and reversed in the DC posi tion Ensure that the range selected will not damage the semiconductor Refer to Table 1 1 item 8 and review the speci fication limits of the semiconductor ac cording to the manufacturer s ratings If the semiconductor is a silicon diode or conventional silicon transistor pre cautions are not normally required o o RS A A o Aa o S Mm 10000 COMMON E Figure 4 13 Jacks and Switch Positions for Measuring Resistance ZERO OHMS ALTERMINALSVMAK LL LEN If the se
39. the cover to the externally accessible battery com partment by loosening the single captivated screw NOTE Batteries should be replaced before their useful life has expired Failure to do so may result in corrosion and battery leakage d Observe polarity when replacing the 1 5 volt D cell and connect as indicated The D cell is held in place with spring clips which also act as battery contact clips The 9 volt battery contacts and connector are polarized To remove the 9 volt battery first withdraw battery with mated connector from the compart ment Then remove the connector Fuse Replacement The 1 and 2 ampere fuse also the 1A spare is located in the externally acces sible battery and fuse compartment Access to the compartment is obtained by disconnecting the test leads and loosening the single captivated screw on the compartment cover To replace or check a fuse Apply pressure to the 1 amp fuse cup then rotate the plate to expose a selected fuse for removal from the panel s cavity NOTE When you replace a fuse make sure it is the same type and value as the fuse you have just removed 27 5 4 5 5 Test Lead Inspection Periodic inspection of the test leads is recommended to detect cuts burned areas dete rioration or other damage that could reduce the insulation strength of leads Care Immediately clean all spilled materials from the Instrument and wipe dry If the spillage is corrosive use a suitable cleaner to
40. tries measure in terms of voltage or current ratios decibels based on a specific reference level The dB scale on the 260 8P serves this purpose and is calibrated to a reference level zero dB or 0 001 watt into 600 ohms The scale calibration of 20 to 10 dB is for the 0 2 5V range zero dB 0 775V Higher ranges may be used by adding an appropriate dB value to the reading in accor dance with the chart below a Review the safety precautions in paragraph 4 1 b Refer to Figure 4 11 for switch settings and jack connections c Use operating instructions for AC VOLTAGE MEASUREMENT 0 2 5 10 25 50 250V RANGES paragraph 4 6 1 Do not use the 500V or 1000V ranges for decibel readings d Read decibels on the bottom scale marked dB For the 10 25 50 250V ranges add the appropriate factor from the following chart maner rner ne 22 NOTE The maximum voltage ratio that can be measured is 50 dB on the 0 250V range e 4 9 e If dB measurements are being made to a 0 006 watt into 500 ohm reference level subtract 7 dB from the reading obtained on the 260 Direct Current Measurement A Do not change the range setting of the range or function switches while the circuit is energized Never disconnect test leads from the circuit under measurement while it is energized Always turn the power off and dis charge all the capacitors before the setting of the switches is changed or the leads disconnected Nev
41. ty contact the nearest Authorized Service Center for instructions If necessary contact the fac tory directly give full details of any installation difficulty and include the Instru ment model number series number and date of purchase Service data or ship ping instructions will be mailed promptly If an estimate of charges for non war ranty or other service work is required a maximum charge estimate will be quoted This charge will not be exceeded without prior approval 2 3 Shipping Pack the Instrument carefully and ship it prepaid and insured 2 4 Power Source Requirements There are two batteries in the ohmmeter circuits a NEDA 13F D size cell that furnishes 1 5 volts for the R X 1 and R X 100 ranges and a NEDA 1604A battery that furnishes 9 volts for the R X 10 000 range The 1 5 volt D cell is held in place with two spring clips which also serve as battery contacts The 9 volt battery is held in place with a spring clip but contact is made with a separate connector that is polarized Always observe correct polarity when replacing the 1 5 volt D cell 2 5 Operating Position A handle is attached to the side of the Instrument case The handle may be used to support the Instrument in a convenient sloping position for easy viewing The VOM case can also be placed either in a vertical or horizontal position The horizontal position is preferable for greater accuracy since the Instrument is cali brated in this position 3 CONT
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