Calibration Procedures

This section contains procedures for adjusting the instrument’s performance (calibration).

Note

There is no separate calibration for Diode or Continuity, because these functions are based on the resistance measurement, which is calibrated. Also, there is no calibration for gate time because this functionality is controlled by digital logic. There is no calibration for capacitance gain and, for the 34465A and 34470A, no calibration on the 1, 10, and 100 µA DCI ranges

Use one of the following sets of procedures based on the DMM model number:

Closed–Case Electronic Calibration

The instrument uses closed-case electronic calibration; no internal mechanical adjustments are required. The instrument calculates correction factors based on reference signals that you apply and stores the correction factors in non-volatile memory. This data is not changed by cycling power, *RST, or SYSTem:PRESet.

Keysight Technologies Calibration Services

Keysight Technologies offers calibration services using automated calibration systems that enable Keysight to provide calibration at competitive prices. See Types of Service Available for information on contacting Keysight.

Calibration Adjustment Interval

The instrument should be calibrated on a regular interval determined by the accuracy requirements of your application. A 1-year interval is adequate for most applications. Accuracy specifications are warranted only if calibration is made at regular calibration intervals. Keysight Technologies never recommends calibration adjustment intervals beyond two years.

Calibration is Recommended

Whatever calibration interval you select, Keysight Technologies recommends that complete re-calibration should always be performed at the calibration interval. This ensures that the instrument will remain within specifications for the next calibration interval and provides the best long-term stability. Performance data measured during performance verification tests does not mean that the instrument will remain within these limits unless the calibration adjustments are performed. Use the calibration count to verify that all calibration adjustments have been performed.

Time Required for Calibration Adjustment

The instrument can be automatically calibrated under computer control, including complete calibration adjustment procedure and performance verification tests, in less than 30 minutes once the instrument is warmed–up (see Test Considerations).

Automating Calibration Adjustment Procedures

The calibration procedures demonstrate front panel calibration. You can automate the complete verification and calibration procedures outlined in this manual. You can program the instrument configurations specified for each test over the remote interface. You can then enter read back verification data into a test program and compare the results to the appropriate test limit values.

The instrument must be unsecured to calibrate. See Calibration Security for details.

Refer to the CALibration Subsystem for information on SCPI programming.

Input Connections

Test connections to the instrument are best accomplished using a Keysight Technologies 34172B calibration short for low–thermal offset measurements and a 34171B DMM connector configured to interface to the calibrator output. Shielded, twisted–pair, PTFE interconnect cables of minimum length are recommended between the calibrator and the multimeter to reduce settling and noise errors. HI and HI Sense should be a twisted pair. LO and LO Sense should be a twisted pair. Cable shields should be earth ground referenced. This configuration is recommended for noise reduction and settling time performance during calibration.

Test Considerations

Errors may be induced by AC signals present on the input leads during a self–test. Long test leads can also act as an antenna causing pick–up of AC signals.

For optimum performance:

Because the instrument is capable of making highly accurate measurements, you must take care to ensure that the calibration standards and test procedures do not introduce additional errors. Ideally, the standards used to verify and adjust the instrument should be an order of magnitude more accurate than each instrument range full scale error specification.

For 2-wire ohms measurements, remove lead resistance by doing a null measurement with the leads shorted or with a precision 4–terminal low thermal short. For offset calibration a 4–terminal low thermal short is required.

Recommended Test Equipment

The recommended test equipment for the performance verification and calibration is listed below. If the exact instrument is not available, substitute calibration standards of equivalent accuracy.

An alternate method is to use the Keysight 3458A 8½-digit Digital Multimeter to measure less accurate, yet stable, sources. The output value measured from the source can be entered into the instrument as the target calibration value.

Application Recommended Equipment
Zero Calibration Keysight 34172B
DC Voltage Fluke 5720A
DC Current Fluke 5720A
Resistance Fluke 5720A
AC Voltage Fluke 5720A
AC Current Fluke 5720A
Frequency Keysight 33500B Series Function/Arbitrary Waveform Generator
High Current Fluke 5725A
Capacitance (Optional) SCA-1uF Capacitance Standard