Model 6514 System Electrometer Quick Results Guide A GREATER MEASURE OF CONFIDENCE
WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
Model 6514 System Electrometer Quick Results Guide ©2003, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. First Printing, May 2003 Document Number: 6514-903-01 Rev.
Manual Print History The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially.
Safety Precautions The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present. This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury.
bles or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers. Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
Table of Contents Introduction ................................................................................... 1 Measurement capabilities .............................................................. 1 Front and rear panels ..................................................................... 2 Basic connections .......................................................................... 3 Input connector ...................................................................... 3 Low noise input cables ....
List of Illustrations 1 Quick Results Guide Figure 1-1 Figure 1-2 Figure 1-3 Figure 1-4 Front panel ................................................................................ Rear panel ................................................................................. Input connector ......................................................................... Basic connections for unguarded measurements ...........................................................................
List of Tables 1 Quick Results Guide Table 1-1 Table 1-2 Table 1-3 Table 1-4 Table 1-5 Table 1-6 Table 1-7 Table 1-8 Table 1-9 Table 1-10 Table 1-11 Table 1-12 Table 1-13 Table 1-14 Volts and ohms measurement procedure .................................. 6 Amps measurement procedure .................................................. 7 Charge measurement procedure ................................................ 7 SCPI commands for basic measurements .................................
Model 6514 System Electrometer Quick Results Guide Introduction This guide is designed to familiarize users with fundamental operation (front panel and remote) of the Keithley Model 6514 System Electrometer. For comprehensive information on all aspects of Electrometer operation, refer to the Model 6514 Instruction Manual. Operation information in this guide is divided into three parts: (1) basic operation, (2) Settings to optimize performance, and (3) Features to enhance DUT testing.
2 Model 6514 Quick Results Guide Front and rear panels The front and rear panels of the Model 6514 are shown in Figures 1 and 2. The use of the various instrument controls and connectors will be explained throughout this guide.
Model 6514 Quick Results Guide 3 Basic connections WARNING The maximum common-mode input voltage, which is the voltage between the input (HI or LO) and chassis ground, is 500V peak. Exceeding this value may create a shock hazard. CAUTION Connecting PREAMP OUT, COMMON, or 2V ANALOG OUTPUT to earth while floating the input may damage the instrument. Input connector The rear panel INPUT connector is a 3-lug female triax connector that will mate to a cable terminated with a male triax connector.
4 Model 6514 Quick Results Guide Figure 3 Input connector Input High Input Low INPUT 250V PEAK Chassis Ground Volts, Amps, Ohms & Coulombs A. Unguarded (GRD off) Input High 0.1Ω Guard Chassis Ground INPUT 250V PEAK Volts and Ohms only Fuse COMMON Input Low B. Guarded (GRD on) Basic connections to DUT Unguarded connections Basic unguarded connections are shown in Figure 4. The DUT is the voltage, current, resistance, or charge to be measured.
Model 6514 Quick Results Guide 5 Guarded connections The basic guarded connections for volts and ohms are shown in Figure 5. With guard (GRD) on, the driven guard is available at the inner shell of the triax connector which is connected to the metal guard plate. The driven guard is used to eliminate leakage current and capacitance in high impedance circuits that could corrupt the volts or ohms measurement. WARNING The guard voltage is at the same potential as the input.
6 Model 6514 Quick Results Guide Basic operation Selecting operating modes Most front panel keys have a dual operation or function. The nomenclature on a key indicates its primary or unshifted function or operation. The nomenclature above a key indicates its shifted function or operation. To select a primary function press the corresponding key. To select a shifted function, press SHIFT first and then the desired key. For example, press AVG to select the digital filter.
Model 6514 Quick Results Guide Making amps measurements The basic procedure to make amps measurements is provided in Table 2. Table 2 Amps measurement procedure Procedure Details 1. Enable zero check. Press ZCHK to enable zero check before making connection changes or selecting function. Press I to measure current. Press ZCOR to zero correct 6514 for maximum accuracy. Use RANGE 5 and 6 keys to manually select range. Or press AUTO RANGE (AUTO annunciator on) to enable auto range. See Figure 4.
8 Model 6514 Quick Results Guide Measurement considerations For sensitive measurements, keep these points in mind to maximize measurement accuracy: • • • Use only low noise triax cable for input connections. Use zero correct with zero check enabled to null internal offsets. Keep the Model 6514 and test circuit away from electrical noise sources, and shield if necessary. Remote command programming Data string The :READ? command is typically used to trigger a reading and request the data string.
Model 6514 Quick Results Guide 9 SCPI commands SCPI commands to make basic measurements are provided in Table 4. Table 4 SCPI commands for basic measurements Command* Description [:SENSe[1]]:FUNCtion Select function: ‘VOLTage’, ‘CURRent’, ‘RESistance’, or ‘CHARge’. Select measure range; = range. Enable/disable auto range; (ON or OFF). Enable (ON) or disable (OFF) guard for volts. Enable (ON) or disable (OFF) guard for ohms. Enable (ON) or disable (OFF) zero check.
10 Model 6514 Quick Results Guide Table 6 Command sequence for amps measurement example Command* Comments *RST SENS:FUNC ‘CURR’ SENS:CURR:RANG:AUTO ON SYST:ZCH OFF READ? Restore GPIB defaults. Select amps measurement function. Enable auto range. Disable zero check. Trigger and acquire one current reading. *Model 6514 must be addressed to talk after sending :READ? to trigger and acquire data.
Model 6514 Quick Results Guide 11 Rate The RATE key selects the integration time of the A/D converter. This is the period of time the input signal is measured. The integration time affects the amount of reading noise, as well as the ultimate reading rate of the instrument. The integration time is specified in parameters based on a number of power line cycles (NPLC), where 1 PLC for 60Hz is 16.67msec (1/60) and 1 PLC for 50Hz (and 400Hz) is 20msec (1/50).
12 Model 6514 Quick Results Guide With both filters enabled, the median filter operation is performed first. After the median filter yields a reading, it is sent to the stack of the digital filter. Therefore, a filtered reading will not be displayed until both filter operations are completed. The settings for the filter are global. Therefore, the filter configuration applies to all four measurement functions.
Model 6514 Quick Results Guide 13 Remote command programming The SCPI commands for speed, digits, filter, and rel are listed in Table 8. The commands for ranging are listed in Table 4. Table 8 SCPI commands: rate, digits, filter, and rel Command Description Rate commands: [:SENSe[1]]:VOLTage:NPLCycles [:SENSe[1]]:CURRent:NPLCycles [:SENSe[1]]:RESistance:NPLCycles [:SENSe[1]]:CHARge:NPLCycles Set voltage rate in PLCs: 0.01 to 10. Set current rate in PLCs: 0.01 to 10.
14 Model 6514 Quick Results Guide Features to enhance DUT testing Buffer The Model 6514 has a buffer to store from one to 2500 readings. It also stores overflow readings and includes a timestamp. In addition, recalled data includes statistical information (minimum, maximum, peak-to-peak, average, and standard deviation). The buffer fills with the specified number of readings and stops. Readings are placed in the buffer after any math operations are performed.
Model 6514 Quick Results Guide • 15 The STD DEV value is the standard deviation of the buffered readings. The equation used to calculate the standard deviation is: n 2 1 -X X – ∑ i n ∑ i 2 i = 1 y= i = 1 -------------------------------------------------------------n-1 n where: Xi is a stored reading. n is the number of stored readings. NOTE The Model 6514 uses IEEE-754 floating point format for math calculations.
16 Model 6514 Quick Results Guide Programming example Table 10 shows a typical command sequence to store and recall readings and mean buffer statistics. Table 10 Command sequence for buffer example Command* Comments :TRAC:POIN 20 :TRAC:FEED SENS :TRAC:FEED:CONT NEXT :TRAC:DATA? :CALC3:FORM MEAN :CALC3:DATA? Set buffer size to 20, Set to store raw readings. Start storing readings. Request all stored readings.* Select mean calculation. Perform calculation and request result.
Model 6514 Quick Results Guide 17 Configuring limit tests Press SHIFT then CONF-LIM, then select LIMIT 1 or LIMIT 2. Use CONTROL to enable the test, then enter your HILIM and LOLIM values (-9.999999T to +9.999999T). (Place the cursor on the + or - keys to change polarity or the desired range symbol to change range.) Once limit tests are configured, use the LIMIT key to start and stop the limit test. Results are displayed as summarized in Table 11.
18 Model 6514 Quick Results Guide Table 13 Command sequence for limit test example Command* Comments *RST :CALC2:LIM:LOW -1 :CALC2:LIM:UPP 1 :CALC2:LIM:STAT ON :CALC2:LIM2:LOW -0.1 :CALC2:LIM2:UPP 0.1 :CALC2:LIM2:STAT ON :READ? :CALC2:LIM:FAIL? :CALC2:LIM2:FAIL? Restore GPIB defaults. Set Limit 1 lower limit to -1. Set Limit 1upper limit to 1. Enable Limit 1 test. Set Limit 2 lower limit to -0.1. Set Limit 2 upper limit to 0.1. Enable Limit 2 test. Trigger and request a reading.
Model 6514 Quick Results Guide 19 To configure and enable the percent function, press SHIFT then %. Enter the desired reference value, then press ENTER. The MATH annunciator will turn on to indicate that percent is enabled. Press SHIFT then % again to disable the function. The MATH annunciator will turn off. Remote mX+b and percent programming SCPI commands Table 14 summarizes commands used for mX+b and percent.
Index B Buffer statistics 14 M mX+b 18 P Percent (%) 18 R Ratio programming example 19 REL Key 12
Specifications are subject to change without notice. All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other trademarks and trade names are the property of their respective companies. Keithley Instruments, Inc. 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: 440-248-6168 1-888-KEITHLEY (534-8453) • www.keithley.
