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Service Information

4-3

4.3.4 Offset current tests

Offset current tests are performed by measuring the residual

current  of  each  Model  6521/22  channel  by  closing  each

channel in succession and then measuring the offset current

using the Model 6517 Electrometer. 

Proceed as follows:

1. With the power off, install the Model 6521/22 Scanner

Card in the Model 6517 OPTION SLOT.

2. Connect the scanner card triax output cable to the Model

6517  INPUT  jack.  (See  Figure  4-1.)  Also  install  the

BNC (Model 6521) or triax (Model 6522) shielding cap

on each channel 1 input cable connector.

3. Program the Model 6517 for the current scan mode (see

paragraph 3.4.4).

4. Turn on the electrometer, and allow a one-hour warm-up

period before performing the offset current tests.

5. Select  the  electrometer  amps  function  and  the  20pA

range. Leave zero check enabled for the time being.

6. Press  the  OPTION  CARD  button,  then  use  the

CHANNEL-CLOSURES  menu  to  close  channel  1  on

the scanner card.

7. Disable zero check, and allow the reading to settle.

8. Verify that the Model 6517 current reading, which rep-

resents the scanner card offset current, is <1pA.

9. Enable zero check, then open channel 1.

10. Repeat steps 6 through 9 for channels 2 through 10. For

each channel, be sure to connect the shielding cap to the

input cable, close the appropriate channel, then verify

that the offset current is <1pA. 

Figure 4-1

Connections for offset current verificatio

Model 

6517 

Electrometer

Triax Cable

Install

Shielding

Caps on

Inputs

H
L IN 1

H
L IN 10

IN 2....9

H

L

G

OUT

HI

LO

Ground

Model 6521

Note:  Model 6522 connection

           is the same except for

           triax input.

WARNING:

NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

WARNING:

NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:

FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

CAUTION:

FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

INPUT

250V PEAK

!

LINE RATING

50-60HZ

50VA MAX

AC ONLY

LINE FUSE

SLOWBLOW

1/2A 90-125V

1/4A 180-250V

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

DIGITAL 

I/O

TRIG LINK

115V

Содержание 6521

Страница 1: ...urrent Model 6522Voltage Current Scanner Cards Instruction Manual A G R E A T E R M E A S U R E O F C O N F I D E N C E Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 TestEqui...

Страница 2: ...ND EXCLUSIVE REMEDIES NEITHER KEITHLEY INSTRUMENTS INC NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU...

Страница 3: ...w Current Scanner Card Model 6522 Voltage Current Scanner Card Instruction Manual 1994 Keithley Instruments Inc All rights reserved Cleveland Ohio U S A Second Printing April 2001 Document Number 6521...

Страница 4: ...red sequentially When a new Revision is created all Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual Each new Revision includes a revise...

Страница 5: ...I O connections are for connection to Category I sources un less otherwise marked or described in the Manual Exercise extreme caution when a shock hazard is present Lethal voltage may be present on ca...

Страница 6: ...lly before performing the indicated procedure The CAUTION heading in a manual explains hazards that could damage the instrument Such damage may invalidate the warranty Instrumentation and accessories...

Страница 7: ...meter 2 Scan speeds are for fixed range readings for 200V and 20mA 6517 ranges into data buffer 3 6517 Filter off speed fast settling time 0 seconds CONNECTOR TYPE Inputs BNC Outputs Triaxial SIGNAL L...

Страница 8: ...6517 Electrometer 2 Scan speeds are for fixed range readings for 200V and 20mA 6517 ranges into data buffer 3 6517 Filter off speed fast settling time 0 seconds CONNECTOR TYPE Inputs Triaxial Outputs...

Страница 9: ...8 Repacking for shipment 1 2 1 9 Optional accessories 1 2 1 9 1 Model 6521 accessories 1 2 1 9 2 Model 6522 accessories 1 3 2 Card Connections and Installation 2 1 Introduction 2 1 2 2 Handling preca...

Страница 10: ...3 6 4 Keeping connectors clean 3 10 3 6 5 Guarded operation 3 10 3 6 6 Voltage current scan mode 3 10 3 7 Typical applications 3 11 3 7 1 Capacitor leakage measurements 3 11 3 7 2 High resistance mea...

Страница 11: ...4 6 2 Troubleshooting access 4 9 4 6 3 Troubleshooting procedure 4 9 5 Replaceable Parts 5 1 Introduction 5 1 5 2 Parts lists 5 1 5 3 Ordering information 5 1 5 4 Factory service 5 1 5 5 Component lay...

Страница 12: ...iv...

Страница 13: ...2 6 Figure 2 11 Output connections 2 7 3 Operation Figure 3 1 Path isolation resistance 3 8 Figure 3 2 Voltage attenuation by path isolation resistance 3 9 Figure 3 3 Power line ground loops 3 9 Figur...

Страница 14: ...vi...

Страница 15: ...able 3 2 Card configuration menu 3 3 Table 3 3 Summary of IEEE 488 bus scanner commands 3 6 4 Service Information Table 4 1 Recommended verification equipment 4 2 Table 4 2 Recommended troubleshooting...

Страница 16: ...viii...

Страница 17: ...ent switching BNC input cables and a triax output cable to maintain signal integrity Low offset current 1pA 30fA typical 1 2 2 Model 6522 features Key Model 6522 features include 10 channels of single...

Страница 18: ...bag observe the precautions on handling discussed below 1 7 2 Handling precautions Always grasp the card by the side edges and covers Do not touch the board surfaces or components After removing the c...

Страница 19: ...igator clips on the other end Recommend ed for extending Model 6522 input connections Model 6171 Adapter 3 slot male to 2 lug female triax adapter Recommended for adapting 2 slot triax cables to Model...

Страница 20: ...General Information 1 4...

Страница 21: ...en when handling the scanner card to avoid contamination from such foreign materials as body oils Such contamination can substantially lower leakage resis tances and increase offset currents degrading...

Страница 22: ...ngle output Note that each channel utilizes single pole switching with only the HI signal path switched Input connections include H HI L LO and G chassis ground while output connections in clude H L a...

Страница 23: ...typical connecting schemes for using the scanner card for amps volts ohms and coulombs measurements NOTE The Model 6521 is intended for current measurements The Model 6522 is de signed for all Model...

Страница 24: ...ns how to install and remove the Model 6521 22 card assembly from the Model 6517 Electrometer WARNING Installation or removal of the Model 6521 22 should be performed only by qualified service personn...

Страница 25: ...plate 2 Slide the card edges into the guide rails inside the electrometer 3 Carefully push the card all the way forward until it seats in the internal connector 4 After the card is fully seated tighte...

Страница 26: ...Card Connections and Installation 2 6 Warning Secure mounting screw to assure proper grounding Figure 2 10 Scanner card installation...

Страница 27: ...including the Model 6517 Electrome ter and disconnect all line cords Make sure all power is removed and any stored energy in external circuitry is dis charged 1 Loosen the mounting screw 2 Carefully s...

Страница 28: ...Card Connections and Installation 2 8...

Страница 29: ...when using the scanner card with the Model 6517 3 7 Typical applications Discusses typical applications for the Model 6521 22 NOTE Before using the Model 6521 22 scanner card you should be thoroughly...

Страница 30: ...that no scanner is present 3 3 2 Scanner option bus query OPT is an IEEE 488 2 common query which will allow you determine whether or not the Model 6521 22 card is in stalled The response to this quer...

Страница 31: ...lect channels in scan list Select voltage or current mode Select voltage source limit Set settling time Configure xternal scan Access card configuration menu by pressing CONFIG then CARD Opening chann...

Страница 32: ...ress ENTER and note that the in strument displays the following message INTERNAL SCANNER CHANNELS SCAN MODE VSRC LIMIT SETTLING TIME 3 Select SCAN MODE then press ENTER The instru ment will display th...

Страница 33: ...selectYES otherwise choose no then press ENTER 9 Assuming that you chose to store readings in the buffer the instrument will display the following 00100 RDGS TO BUFFER Press ENTER to continue 10 Press...

Страница 34: ...els Query open channels Scanning commands Program internal scan list Query internal scan list Program external scan number of channels 1 n 400 Query external scan number of channels Select scan list Q...

Страница 35: ...er card Configure the scanner card as outlined previously For exam ple the following commands will program the card for a set tling time of 100msec current operation and a voltage source limit of 200V...

Страница 36: ...t through circuitry connected to the scanner card To minimize the effects of dielectric absorption avoid apply ing more than a few volts to the input or output connectors of a scanner card to be used...

Страница 37: ...these instances special precautions may be required in the test setup Sources of EMI include Radio and TV broadcast transmitters Communications transmitters including cellular phones and handheld radi...

Страница 38: ...lead with a guard signal that is driven by the low im pedance electrometer preamp output Since the guard shield is at the same potential as the HI signal lead no leakage cur Instrument 1 Instrument 2...

Страница 39: ...test a number of capacitors The system in cludes a Model 6517 Electrometer to apply test voltages and measure leakage currents while the Model 6521 22 Scanner card provides the necessary switching fu...

Страница 40: ...used for the test fixture All insulators throughout should be made of a mate rial with very high resistance such as Teflon Any residual leakage current can be nulled out by suppressing the mea sured c...

Страница 41: ...R SERVICABLE PARTS SERVICE BY QUALIFIED PERSONNEL ONLY CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE FUSE WITH SAME TYPE AND RATING CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD...

Страница 42: ...Operation 3 14...

Страница 43: ...22 including relay replacement pre cautions 4 2 Handling and cleaning precautions Because of the high impedance areas on the Model 6521 22 care should be taken when handling or servicing the card to...

Страница 44: ...rer Model Specifications1 Application Electrometer Digital Multimeter Keithley 6517 Keithley 2001 20pA 1 20G 20T 1 20 79ppm 200mV 44ppm Control card measure offset cur rent isolation Contact resistanc...

Страница 45: ...le zero check and allow the reading to settle 8 Verify that the Model 6517 current reading which rep resents the scanner card offset current is 1pA 9 Enable zero check then open channel 1 10 Repeat st...

Страница 46: ...al of the scanner card output jack with a similar adapter Again refer to Figure 4 2 7 Turn on the Model 6517 power 8 Press the OPTION CARD button then use the CHANNEL CLOSURES menu to close channel 1...

Страница 47: ...CAL DCV ACV DCI ACI 2 4 FREQ TEMP 2001 MULTIMETER RANGE F 500V PEAK FRONT REAR 2A 250V AMPS HI INPUT LO SENSE 4 WIRE INPUTS 350V PEAK 1100V PEAK AUTO PREV NEXT DISPLAY POWER RANGE R CAL 1 2 3 4 5 6 7...

Страница 48: ...he CHANNEL CLOSURES menu to close channel 1 Program the volt age source for 200V and then turn on the Model 6517 voltage source 6 Verify that the Model 6517 resistance reading is 10T 7 Turn off the vo...

Страница 49: ...A MAX AC ONLY LINE FUSE SLOWBLOW 1 2A 90 125V 1 4A 180 250V IEEE 488 CHANGE IEEE ADDRESS WITH FRONT PANEL MENU DIGITAL I O TRIG LINK 115V Figure 4 5 Connections for input isolation Model 6517 Electrom...

Страница 50: ...ata control cir cuits the relay drivers and relays and the power up reset cir cuit These various elements are discussed in the following paragraphs 4 5 2 Relay control Card relays are controlled by se...

Страница 51: ...ng hole completely free of solder Each relay pin must be free to move in its mounting hole before removal Also make certain that no burrs are present on the ends of the relay pins 4 6 Troubleshooting...

Страница 52: ...34 pin 9 U102 pin 2 U102 pin 3 U102 pin 7 U102 U104 pins 10 18 5VDC CLK pulses DATA pulses STR pulse Low with relay All voltages referenced to digital ground Card power supply voltage During relay upd...

Страница 53: ...g information Card model number 6521 22 Card serial number Part description Circuit description if applicable Keithley part number 5 4 Factory service If the card is to be returned to Keithley Instrum...

Страница 54: ...FOR OUTPUT 4 40X5 16 PHILLIPS PAN HD SEMS CAP 1UF 20 50V CERAMIC 1206 CAP 10UF 20 25V TANTALUM D7243 CAP 100UF 20 16V TANTALUM 7243 RELAY 1FORMA COTO 1203 0147 CONNECTOR FEMALE 48 PIN RES 4 7K 5 125M...

Страница 55: ...UT 4 40X5 16 PHILLIPS PAN HD SEMS CAP 1UF 20 50V CERAMIC 1206 CAP 10UF 20 25V TANTALUM D7243 CAP 100UF 20 16V TANTALUM 7243 RELAY 1FORMA COTO 1203 0147 CONNECTOR FEMALE 48 PIN RES 4 7K 5 125MW METAL F...

Страница 56: ...Replaceable Parts 5 4...

Страница 57: ......

Страница 58: ......

Страница 59: ......

Страница 60: ...rations 3 7 Model 6521 accessories 1 2 Model 6521 features 1 1 Model 6521 scanner card configuration 2 1 Model 6521 signal limitations 3 1 Model 6521 simplified schematic 2 1 Model 6522 accessories 1...

Страница 61: ...nsiderations 4 1 Special handling of static sensitive devices 4 8 Specifications 1 2 Switching circuits 4 8 T Triboelectric effects 3 8 Troubleshooting 4 9 Troubleshooting access 4 9 Troubleshooting e...

Страница 62: ...nstable Will not read applied input Overload Calibration only Certi cate of calibration required Data required attach any additional sheets as necessary Show a block diagram of your measurement system...

Страница 63: ......

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Страница 65: ...40 Fax 089 84 93 07 34 GREAT BRITAIN Keithley Instruments Ltd The Minster 58 Portman Road Reading Berkshire RG30 1EA 0118 9 57 56 66 Fax 0118 9 59 64 69 INDIA Keithley Instruments GmbH Flat 2B WILLOC...

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