Ohmmeter Replacement Guide

Transcription

1 Ohmmeter Replacement Guide (From 3560 to RM3545) 1. Measurement 2. Functionality 3. External Control (EXT I/O) 4. Commands Please prepare copies of the user manuals for the old and new instruments and review the applicable sections of each. If you do not have access to these manuals, they can be downloaded in PDF format from your myhioki website. Please note that this guide may be revised or up dated without notice.

2 1. Measurement (1) Resistance measurement method (difference between DC and AC) The 3560 and RM3545 use different resistance measurement methods. The 3560 uses AC measurement, while the RM3545 uses DC measurement. These methods differ as follows: Resistance (impedance) measurement can be performed using the DC or AC method. DC method RM3542, RM3543, RM3544, RM3545, RM3548 resistance meters Standard digital multimeters Standard insulation resistance meters AC method 3561, BT3562, BT3563, 3554 Battery HiTesters Standard LCR meters The DC measurement method is used widely in applications such as measurement of general-purpose resistors, winding resistance, contact resistance, and insulation resistance. Inthe DC method, the measurement setup consists of a DC power supply and a DC voltmeter. While its simple circuitry makes it easier to increase accuracy, it is prone to measurement errors due to electromotive force that may be present in the measurement path. See: "Appendix 9 Effect of Thermal EMF" (RM3545 Instruction Manual p.a23) The AC method is used when it is not possible to measure using DC, for example in impedance measurement of inductors, capacitors, or batteries. Since an AC ohmmeter consists of an AC power supply and an AC voltmeter, it is not affected by DC electromotive force. On the other hand, caution is necessary since results differ from those obtained using DC measurement, for example due to components such as core loss in coils series equivalent resistance. Measurement signal Detection voltage DC ohmmeter AC ohmmeter DC AC Advantages High-precision measurement is possible. Not affected by electromotive force. Reactance measurement is possible. Disadvantages Affected by electromotive force since not capable of Difficult to increase precision. performing DC superimposed measurement. (Thermal EMFs can be corrected by the OVC function.) Applications DC resistance of windings such as transformers and Battery impedance, inductors, capacitors, motors, contact resistance, insulation resistance, electrochemical measurement PCB wiring resistance Measurement range 10-8 to to 10 8 Hioki instruments Ohmmeters : RM3542 to RM3548 DMMs : 3237 to 3238 Insulation resistance meters : IR4000 series, DSM series Battery HiTesters : 3561, BT3562, BT3563 LCR meters : 3570, IM3533, IM3523, etc. 1 Jan. 30, 2014

3 The purpose of AC resistance measurement is to eliminate the offset voltage. The RM3545 s OVC function plays the same role. The OVC function is always on during low-power resistance measurement. Due to the skin effect, the DC and AC values for thick materials differ (for example, at a depth of approximately 2.1 mm on a copper skin at 1 khz). JIS C 5442, Test methods of low-power electromagnetic relays for industrial control circuits, defines applicable test methods and includes the following items: 4.5.2(2) When using a DC voltage, measurement shall be performed by reversing switch S so as to switch the electrode polarity. The described functionality corresponds to the RM3545 s OVC function (1) Either a DC or AC power supply may be used for measurement, but the measured value obtained from DC measurement shall be used in the event that there is doubt as to the accuracy of the measured value. See: (2) Range structure comparison 3560 (For SLOW/MEDIUM, limiter is ON) RM3545 (Low-power setting is ON) Range Display range Measurement current With the low-power setting on, the RM3545 has a maximum open voltage of 20 mv, like the 3560 (when the voltage limiter is on). How to set the number of display digits Menu [P.2/2] Setting screen (SETTING) Measurement Setting screen (MEAS) Low-power resistance measurement (LOW POWER) The 3560 and RM3545 have different range structures. When setting the range by command, an optimal range is selected based on the setting value. The RM3545 provides a six-digit display (when the low-power setting is on). The number of display digits can be changed (from five to seven). How to set the number of display digits Open terminal voltage Range Display range Measurement current Open terminal voltage 30mΩ mΩ 7.4mA mΩ mΩ 1mA Ω Ω 100μA 1000mΩ mΩ 1mA 20mV max 30Ω Ω 10μA 10Ω mΩ 500μA 20mV max 300Ω Ω 5μA 100Ω Ω 50μA 3kΩ kΩ 1.5μA 1000Ω Ω 5μA Menu [P.2/2] Setting screen (SETTING) Measurement Setting screen (MEAS) Number of measurement digits (Ω DIGITS) (3) Measurement leads Use of 3560 measurement leads ( , etc.) with the RM3545 is not recommended (and doing so will place the performance of the instrument outside the accuracy guarantee). The leads that come with the RM3545 and optional measurement leads (L2101, etc.) include a guard terminal in order to reduce the effects of external noise. Although there is no difference in the leads center value (average value), use of the 3560 measurement leads with the new instrument will make measurement more susceptible to the effects of noise, so their performance should be verified in the environment in which they are to be used first. If you plan to make your own measurement leads, refers to Appendix 10: Making Your Own Measurement Leads in the RM Jan. 30, 2014

4 2. Functionality (1) Hold function The RM3545 incorporates an auto-hold function. Please note that the manner in which this function operates differs from the 3560 s hold function. If you have been using the 3560 s hold function in combination with its EXT I/O functionality, change the RM3545 s trigger source to external trigger [EXT]. How to change the trigger source setting Menu [P.2/2] Setting screen (SETTING) EXT I/O Setting screen (I/O) Set the trigger source (TRIG SOURCE) to external trigger (EXT). (2) Manual comparator The RM3545 does not provide functionality that corresponds to the 3560 s manual comparator function (MANU signal). (3) Comparator table The RM3545 s panel load function corresponds to the 3560 s comparator table. Panel data saved Resistance measurement range, measurement speed, zero-adjustment, averaging, comparator, judgment tone, scaling, temperature correction (TC), auto-hold, etc. 3 Jan. 30, 2014

5 3. External Control (EXT I/O) The timing of some aspects of the RM3545 s operation differs from that of the Be sure to review the timing charts in the RM3545 s (1) Switching between current sink (NPN) and current source (PNP) The RM3545 allows you to switch between NPN and PNP operation. To control the instrument in the same way as the 3560, set the NPN/PNP switch to NPN. The instrument ships with the switch in the NPN position. The EXT I/O mode cannot be changed using commands. Left: Current sink (NPN) Right: Current source (PNP) (2) Connector The RM3545 connector is configured as follows: TRIG, IN0 BCD_LOW KEY_LOCK LOAD1 LOAD3 LOAD5 SCN_STOP ISO_5V ISO_COM ERR HI, HILO LO, BCD4-1, RNG_OUT1 T_PASS, BIN0, BCD4-3, RNG_OUT3 T_ERR, BIN2, BCD5-1, BCD1-1 BIN4, BCD5-3, BCD1-3 BIN6, BCD6-1, BCD2-1 BIN8, BCD6-3, BCD2-3 OUT0, BCD7-1, BCD3-1 OUT2, BCD7-3, BCD3-3 Connector: (Instrument Side) 37-pin D-sub female with #4-40 screws Mating Connectors: DC-37P-ULR (solder type) / DCSP-JB37PR (pressure weld type) Japan Aviation Electronics Industry Ltd BIN5, BCD6-0, BCD2-0 BIN7, BCD6-2, BCD2-2 BIN9, BCD7-0, BCD3-0 OUT1, BCD7-2, BCD3-2 T_FAIL, BIN1, BCD5-0, BCD1-0 BIN3, BCD5-2, BCD1-2 IN OB, BCD4-2, RNG_OUT2 INDEX, BCD4-0, RNG_OUT0 EOM ISO_COM PRINT, IN1 MUX 0ADJ CAL LOAD0 LOAD2 LOAD4 4 Jan. 30, 2014

6 (3) Signal table Power Output Description 3560 RM3545 Description 3560 RM3545 Power EXT.DCV ISO_5V Comparator Hi Hi HI Ground/common GND ISO_COM Comparator IN IN IN Input Comparator Lo Lo LO Description 3541 RM3545 Comparator HiLo - HILO TRIG (measurement start) TRIG TRIG Measurement fault NG ERR Zero adjustment 0ADJ 0ADJ Measurement complete EOC EOM Printer output PRINT PRINT Analog measurement complete - INDEX Calibration - CAL Range data output - RNG_OUT Key lock - KEY_LOCK BCD output * - BCDm n BCD low-order byte output* - BCD_LOW - BIN0 to 9 BIN output Table/panel COMP.0 to 4 LOAD0 to 5 - OB General-purpose input - I N0, 1 General-purpose output - OUT0 to 2 Multiplexer - T_PASS MUX Multiplexer - T_FAIL SCN_STOP T_ERR * BCDm-n: Outputs the nth bit of digit m. (BCD1-x is the lowermost digit, while BCDx-0 is the LSB.) 5 Jan. 30, 2014

7 (4) Acquiring judgment results The RM3545 does not provide any functionality that corresponds to the 3560 s manual comparator function (MANU signal). Additionally, the 3560 and RM3545 differ as follows: [3560] The EOC signal turns on 1 ms after TRIG input, and the most recent judgment value is output. The EOC signal consists of a 1 ms pulse. The judgment results are updated while the EOM signal is on but are not cleared. [RM3545] The EOM signal turns on once measurement starts after TRIG input, and the judgment value is output. Off output is generated for the EOM signal once the TRIG signal is accepted. The judgment results are cleared when the TRIG signal turns on. 3560: Hold state timing chart TRIG ON EOC ON 1ms Judgement result/bcd ON/ ON/ RM3545: Timing chart when using the external trigger [EXT] setting TRIG ON EOM ON Judgement result/bcd ON/ 6 Jan. 30, 2014

8 4. Commands As a rule, the RM3545 is not compatible with 3560 messages. Please replace 3560 messages with their corresponding RM3545 messages. To set the open voltage to 20 mv, turn on low-power resistance measurement (LP). The following RM3545 messages are related to low-power resistance measurement: (1) Message correspondence chart 3560 message Corresponding RM3545 message Explanation Low-power resistance measurement (LP) Shared commands *CLS *ESE *ESE? *ESR? *IDN? *OPC *OPC? *RST *SRE *SRE? *STB? *TRG *TST? *WAI Load measured values :MEASure:RESIstance? :MEASure:BATTery? :MEASure:VOLTage? :MODe :MODe? Zero adjustment [:SENSe:]RESistance:LP:STATe [:SENSe:]RESistance:LP:STATe? *CLS *ESE *ESE? *ESR? *IDN? *OPC *OPC? *RST *SRE *SRE? *STB? *TRG *TST? *WAI :FETCh? To set the open voltage to 20 mv, turn on low-power resistance measurement (LP). While shared commands can generally be used, the response from the instrument may differ. See the RM3545 Communications Command User Manual. The format differs. See the Communications Command The RM3545 does not provide voltage measurement functionality. :ADJust? :ADJust? Can be used without modifi cation. :ZERoclear :ADJust:CLEar The format differs. See the Communications Command Measurement speed :SAMPle :SAMPle:RATE The format differs. See the Communications Command :SAMPle? :SAMPle:RATE? Comparator :CSET:BEEPer :CALCulate:LIMit:BEEPer :CSET:BEEPer? :CALCulate:LIMit:BEEPer? The format differs. See the Communications Command :CSET:RPARameter :CALCulate:LIMit:UPPer / :CALCulate:LIMit:LOWer :CSET:RPARameter? :CALCulate:LIMit:UPPer? / :CALCulate:LIMit:LOWer? :CSET:MODe The RM3545 does not provide voltage measurement :CSET:MODe? functionality. :COMParator :CALCulate:LIMit:STATe The RM3545 does not provide a comparator table. Use :CSET:NUMBer :COMParator? :SYSTem:PANel:SAVE :CALCulate:LIMit:STATe? the panel load function as a substitute for the comparator table. Additionally, the comparator can be used without :CSET:NUMBer? :SYSTem:PANel:LOAD saving panel data. :CSET:RRANge :CSET:RRANge? [:SENSe:]RESistance:LP:RANGe [:SENSe:]RESistance:LP:RANGe? The RM3545 uses a shared set of comparator and normal ranges. The range varies depending on whether the LP setting is on or off (when replacing the 3560, use with the LP setting on). 7 Jan. 30, 2014

9 Comparator 3560 message Corresponding RM3545 message Explanation :CSET:VPARameter :CSET:VPARameter? :CSET:VRANge The RM3545 does not provide voltage measurement functionality. :CSET:VRANge? :CTMode :CTMode? :TRIGger:SOURce :TRIGger:SOURce? The RM3545 does not have an external control terminal mode. The trigger source (internal trigger/external trigger) serves as a substitute. For timing charts, see the RM3545 Hold :HOLD [:SENSe:]HOLD:AUTO / :TRIGger:SOURce The RM3545 s hold function acts as an auto-hold function. To stop operation after each measurement, set :HOLD? [:SENSe:]HOLD:AUTO? / :TRIGger:SOURce? the trigger source to external trigger. Measurement range :RRANge [:SENSe:]RESistance:LP:RANGe The format differs. See the Communications Command :RRANge? [:SENSe:]RESistance:LP:RANGe? :AUTorange [:SENSe:]RESistance:RANGe:AUTO The range varies depending on whether the LP setting is on or off (when replacing the 3560, use with the LP :AUTorange? [:SENSe:]RESistance:RANGe:AUTO? setting on). :VRANge :VRANge? Hold :SENSecheck :SENSecheck? [:SENSe:]RESistance:LP:CONTactcheck [:SENSe:]RESistance:LP:CONTactcheck? The format differs. See the Communications Command The range varies depending on whether the LP setting is on or off (when replacing the 3560, use with the LP setting on). Supply frequency :FERQuency :SYSTem:LFRequency The format differs. See the Communications Command :FERQuency? :SYSTem:LFRequency? Communication setting :HEADer :SYSTem:HEADer The format differs. See the Communications Command :HEADer? :SYSTem:HEADer? Lock function :LIMit The RM3545 does not have a limiter function. :LIMit? :LOCK:EXTernal The RM3545 does not have an I/O lock function. :LOCK:EXTernal? :LOCK:KEY :LOCK:KEY? :SYSTem:KLOCk :SYSTem:KLOCk? The format differs. See the Communications Command 8 Jan. 30, 2014

10 Note: Company names and Product names appearing in this catalog are trademarks or registered trademarks of various companies. HIOKI (Shanghai) SALES & TRADING CO., LTD.: TEL FAX / info@hioki.com.cn DISTRIBUTED BY HEADQUARTERS: 81 Koizumi, Ueda, Nagano, , Japan TEL FAX / os-com@hioki.co.jp HIOKI INDIA PRIVATE LIMITED: TEL FAX hioki@hioki.in HIOKI SINGAPORE PTE. LTD.: TEL FAX info-sg@hioki.com.sg HIOKI USA CORPORATION: TEL FAX / hioki@hiokiusa.com HIOKI KOREA CO., LTD.: TEL FAX info-kr@hioki.co.jp All information correct as of Jan. 30, All specifications are subject to change without notice. Printed in Japan