Keithley 6517A Electrometer

Specifications

VOLTS

RANGE	5 1/2-DIGIT RESOLUTION	ACCURACY (1 Year) 18°-28°C ±(%rdg+counts)	TEMPERATURE COEFFICIENT 0°-18°C & 28°-50°C ±(%rdg+counts)/°C
2V	10µV	0.025+ 4	0.003+ 2
20V	100µV	0.025+ 3	0.002+ 1
200V	1mV	0.06+ 3	0.002+ 1

NMRR: 60dB on 2V, 20V, >55dB on 200V, at 50Hz or 60Hz ±0.1%.

CMRR: >120dB at DC, 50Hz or 60Hz.

INPUT IMPEDANCE: >200T in parallel with 20pF, < 2pF guarded (10M with zero check on).

SMALL SIGNAL BANDWIDTH AT PREAMP OUTPUT: Typically 100kHz (–3dB).

AMPS

RANGE	5 1/2 DIGIT RESOLUTION	ACCURACY (1 Year) 18°-28°C ±(%rdg+counts)	TEMPERATURE COEFFICIENT 0°-18°C & 28°-50°C ±(%rdg+counts)/°C
20pA	100aA	1 + 30	0.1 + 5
200pA	1fA	1 + 5	0.1 + 1
2nA	10fA	0.2 + 30	0.1 + 2
20nA	100fA	0.2 + 5	0.03 + 1
200nA	1pA	0.2 + 5	0.03 + 1
2µA	10pA	0.1 + 10	0.005 + 2
20µA	100pA	0.1 + 5	0.005 + 1
200µA	1nA	0.1 + 5	0.005 + 1
2mA	10nA	0.1 + 10	0.008 + 2
20mA	100nA	0.1 + 5	0.008 + 1

INPUT BIAS CURRENT: <3fA at t_CAL temperature coefficient=0.5fA/°C.

INPUT BIAS CURRENT NOISE: <750aA p-p (capped input), 0.1Hz to 10Hz bandwidth, damping on. digital filter =40 readings.

INPUT VOLTAGE BURDEN at T_CAL±1°C: <20µV on 20pA, 2nA, 20nA, 2µA, 20µA ranges. <100µV on200pA, 200nA, 200µA ranges. <2mV on 2mA range. <4mV on 20mA range.

TEMPERATURE COEFFICIENT OF INPUT VOLTAGE BURDEN: <10µv/°C on pa, na, µa ranges.

PREAMP SETTLING TIME (to 1% of final value): 2.5s typical on pA ranges, damping off, 4s typical on pA ranges damping on, 15ms on nA ranges, 2ms on µA and mA ranges.

NMRR: >95dB on pA, 60dB on nA, µA, and mA ranges at 50Hz or 60Hz ±0.1%.

COULOMBS

RANGE	5 1/2-DIGIT RESOLUTION	ACCURACY (1Year) 18°-28°C ±(%rdg+counts)	TEMPERATURE COEFFICIENT 0°-18°C & 28°-50°C ±(%rdg+counts)/°C
2nC	10 fC	0.4 + 5	0.04 + 3
20nC	100 fC	0.4 + 5	0.04 + 1
200nC	1pC	0.4 + 5	0.04 + 1
2µC	10pC	0.4 + 5	0.04 + 1

INPUT BIAS CURRENT: <4fA at T_CAL. Temperature coefficient = 0.5fA/°C.

OHMS (Normal Method)

RANGE	51/2 DIGIT RESOLUTION	ACCURACY (10-100% Range) 18°-28°C (1 Yr.) ±(% rdg+counts)	TEMPERATURE COEFFICIENT (10-100% Range) 0°-18°C & 28°-50°C ±(% rdg+counts)	AUTO V SOURCE	AMPS RANGE
2 M	10	0.125 + 1	0.01 + 1	40 V	200µA
20 M	100	0.125 + 1	0.01 + 1	40 V	20µA
200 M	1 K	0.15 + 1	0.015 + 1	40 V	2µA
2 G	10 K	0.225 + 1	0.035 + 1	40 V	200nA
20 G	100 K	0.225 + 1	0.035 + 1	40 V	20nA
200 G	1 M	0.35 + 1	0.110 + 1	40 V	2nA
2 T	10 M	0.35 + 1	0.110 + 1	400 V	2nA
20 T	100 M	1.025 + 1	0.105 + 1	400 V	200pA
200 T	1 G	1.15 + 1	0.125 + 1	400 V	20pA

PREAMP SETTLING TIME: Add voltage source settling time to preamp settling time in Amps specification

OHMS (Alternating Polarity Method)
The alternating polarity sequence compensates for the background (offset) currents of the material or device under test. Maximum tolerable offset up to full scale of the current range used.
Using Keithley 8002A or 8009 fixture
REPEATABILITY: DI_BG x R/V_ALT + 0.1% (1s) (instrument temperature constant ± 1°C).
ACCURACY: (V_SRCErr + I_MEASErr x R)/V_ALT
where: DI_BG is a measured, typical background current noise from the sample and fixture.

V_ALT is the alternating polarity voltage used.

V_SRCErr is the accuracy (in volts) of the voltage source using V_ALT as the setting.

I_MEASErr is the accuracy (in amps) of the ammeter using V_ALT /R as the rdg.

VOLTAGE SOURCE

RANGE	51/2 DIGIT RESOLUTION	ACCURACY (1 Year) 18°-28°C ±(% setting + offset)	TEMPERATURE COEFFICIENT 0°-18°C & 28°-50°C ±(% setting + offset)/°C
100V	5 mV	0.15 + 10 mV	0.005 + 1mV
1000V	50 mV	0.15 + 100 mV	0.005 + 10mV

MAXIMUM OUTPUT CURRENT: ±10mA; active current limit at <11.5mA for 100V range. ±1mA; active current limit at <1.15mA for 1000V range.

SETTLING TIME: <8ms to rated accuracy for 100v range. <50ms to rated accuracy for 1000v range.

NOISE: <150µV p-p from 0.1Hz to 10Hz for 100V range. <1.5mV p-p from 0.1Hz to 10Hz for 1000V range.

TEMPERATURE (THERMOCOUPLE)

THERMOCOUPLE TYPE	RANGE	ACCURACY (1 Year) 18°-28°C ±(% rdg + °C)
K	25°C to 150°C	± (0.3% + 1.5°C)

HUMIDITY

RANGE	ACCURACY (1 Year) 18°-28°C, ±(% rdg + % RH)
0-100%	± (0.3% +0.5)

Alternating Polarity Method
The Model 6517A uses the Alternating Polarity method, which virtually eliminates the effect of any background currents in the sample. First and second order drifts of the background currents are also canceled out. The Alternating Polarity method applies a voltage of positive polarity, then the current is measured after a specified delay (Measure Time). Next, the polarity is reversed and the current measured again, using the same delay. This process is repeated continuously and the resistance is calculated based on a weighted average of the four most recent current measurements. This method typically produces a highly repeatable, accurate measurement of resistance (or resistivity) by the seventh reversal on most materials (i.e., by discarding the first three readings). For example, a 1mm-thick sample of 10¹⁴ohm-cm material can be measured with 0.3% repeatability in the 8009 test fixture in the Model 65, provided the background current changes less than 200fA over a 15-second period.

Easy to Use
The 6517A begins displaying the calculated resistance (or resistivity) only after the programmed number of readings have been discarded. This provides easy and accurate measurements on difficult materials and devices. The factory default settings of the 6517A (Measure Time, Offset Voltage, Alternating Voltage and Readings to Discard) provide good results on many materials. Different materials and conditions may require different settings - the Model 6524 software simplifies determining the appropriate settings for these cases.

Stand Alone Operation
Once the appropriate settings for the 6517A have been determined via the 6524 software, they can be programmed into the 6517A, stored in internal memory, and used just like the original default settings. Up to ten different settings can be stored in the Model 6517A. Subsequent measurements can then be made using the 6517A and fixtures alone, without the use of the PC or software. All the operations observed via the software are then done internally to the 6517A and only the final resistance/resistivity measurement result is displayed. This is ideal for production testing or repetitive testing of materials or devices.

This graph, using Model 6524 software, shows the actual current waveform that results from the applied Alternating Polarity DC voltage. The square wave represents the alternating applied voltage. From this window, the test engineer can determine whether the parameters entered in the setup window are appropriate for the material or device under test. This picture also demonstrates the Alternating Polarity method. The square boxes show the current measured each time after the programmed Measure (or delay) Time. Then, the polarity of the applied voltage is reversed and another current measurement is made after another Measure Time delay. The ‘x’ shows the calculated current, based on a weighted average of the four previous current measurements. By observing the ‘x’s, it can be seen that the calculated currents are positive, repeatable, and stable and that the effects of background currents and drifts have been eliminated. The square waveform shown here superimposed on the graph represents the alternating applied voltage.

Temperature and Humidity Stamping
To help you make accurate comparisons of readings acquired under varying conditions, the 6517A offers a built-in type K thermocouple and an optional 6517A-RH Relative Humidity Probe.

Accessories Extend Measurement Capabilities
A variety of optional accessories can be used to extend the 6517A's applications and enhance its performance. Two scanner cards are available to simplify scanning multiple signals. Either card can be easily inserted in the option slot of the instrument's back panel. The 6521 Scanner Card offers ten channels of low level current scanning. The 6522 Scanner Card provides ten channels of high impedance voltage switching or low current switching.

Model 8002A High Resistance Test Fixture
The Model 8002A Component Test Fixture is used for making high resistance measurements on devices such as switches, relays, capacitors, insulating terminals, semiconductor packages, headers, and lead frames. It is designed to minimize leakage current, which can become a significant portion of a high resistance measurement if not carefully controlled. A safety interlock feature automatically turns off the instrument's voltage source unless the fixture's lid is firmly closed.

Model 8009 Resistivity Chamber
The Model 8009 Resistivity Test Fixture is designed for measuring the volume and surface resistivity of electronic insulating materials such as dielectric or insulating films. It can also be used to assess the quality of sheets of materials and/or products such as printing paper, photographic film, glass, etc. by measuring the resistance of these items under various conditions. The 6517A already contains the geometric parameters of the 8009 for surface and volume resistivity, which are automatically selected when the user switches the fixture for volume or surface mode.

NIST-Traceable Calibration
The optional 5156 Calibration Unit allows you to acquire NIST-traceable calibration specifications. It includes all the standards needed to calibrate the 6517A's 20pA–2µA current ranges and the 2nC–2µC charge ranges.

Applications
The 6517A is well suited for low current and high impedance voltage, resistance, and charge measurements in areas of research such as physics, optics, and materials science. Its extremely low voltage burden makes it particularly appropriate for use in solar cell applications. Its high speed and ease-of-use also make it an excellent choice for quality control, product engineering, and production test applications involving leakage, breakdown, and resistance testing. Volume and surface resistivity measurements on non-conductive materials are particularly enhanced by the 6517A's voltage reversal method.

The 6524 Package Includes Four Programs: The 6517 Hi-R Test performs the Alternating Polarity Method by a series of commands from the PC to the 6517A (or 6517) and displays current transients resulting from the alternating stimulus voltage, as well as volume resistivity, surface resistivity, or resistance results. It allows the user to change settings easily and observe the results via the PC. This is useful for research and experimentation and for determining the optimum settings for a given material. Since this program does not use the 6517A's internal Alternating Polarity firmware, it can be used with the 6517 to mimic the 6517A's capabilities The 6517 Hi-R Step Response Program plots and analyzes the current transients that result from a single voltage step. It performs a fit to exponential decays to permit analysis of samples with multiple time constants. It allows easy viewing of the step response current in log or linear scale vs. log or linear time and is particularly useful in determining the appropriate measure time setting. Also can be used with the Model 6517. The 6517A Hi-R Sweep Test performs a sequence of Alternating Polarity tests, sweeping one of the following parameters - Alternating Voltage, Offset Voltage, or Measure Time - while measuring current or resistance/resistivity. It uses the Alternating Polarity algorithms included in the 6517A's internal firmware for better timing control. Usable with 6517A only. The 6517A Hi-R, T and RH Program allows plotting resistivity/resistance plus temperature, relative humidity over time. This ability facilitates correlating resistivity resistance measurements with environmental factors. Like the 6517A Hi-R Sweep Test, it uses the Alternating Polarity algorithms included in the 6517A's internal firmware to improve timing control. Usable with 6517A only.