Performance Tests and Calibration 6Keysight U1253B User’s and Service Guide 193Calibration procedures1 Turn the rotary switch to the function you wish to calibrate.2 Unsecure the U1253B true RMS OLED multimeter (refer to “Unsecuring theinstrument for calibration” on page 180).3 After verifying that the security code you entered is correct, the instrument willdisplay the reference input value of the next calibration item (refer to Table 6-4on page 196 for the list and sequence of all the calibration items) on thesecondary display after briefly showing “PASS”.– For example, if the reference input of the next calibration item is shortingthe input terminals, the secondary display will indicate “REF:+SH.ORT”.4 Set up the indicated reference input and apply this input to the correctterminals of the U1253B handheld multimeter. For example:– If the required reference input is “SHORT”, use a shorting plug to short thetwo relevant terminals.– If the required reference input is “OPEN”, just leave the terminals open.– If the required reference input is a voltage, current, resistance, capacitance,or temperature value, set up the Fluke 5520A calibrator (or another devicewith equivalent standard of accuracy) to provide the necessary input.5 With the required reference input applied to the correct terminals, pressto start the present calibration item.6 During calibration, the primary display and bar-graph will indicate theuncalibrated reading, and the calibration indicator, “CAL”, will appear on theupper left corner of the secondary display. If the reading is within theacceptable range, the word “PASS” will be shown momentarily, and then theinstrument will proceed to the next calibration item. If the reading is out of theacceptable range, it will remain at the present calibration item after showingthe error code for 3 seconds. In this case, you need to check whether thecorrect reference input has been applied. Refer to Table 6-5 on page 201 forthe meaning of the error codes.NOTE If you do not intend to perform the complete set of calibration items, you maypress or to select the item you wish to calibrate.
