Used Calibration Equipment for Sale

The 5500A was the original model, supporting DC voltage to 1100 V, AC voltage to 1020 V, DC and AC current, resistance, capacitance, and thermocouple output. The 5520A adds 1 GHz RF output for RF instrument calibration and improves uncertainty figures across most parameters. The 5522A further improves uncertainty — it achieves ±9 ppm 90-day DC voltage accuracy versus ±11 ppm on the 5520A — and adds a USB interface. For calibrating 5.5-digit and 6.5-digit DMMs, the 5520A or 5522A is the standard choice in most accredited labs.

The most common issue we see on the bench is the current output module refusing to produce accurate current above 10 A — this is typically a failing current amplifier transistor or a degraded current shunt resistor. The second is the AC voltage output accuracy drifting from spec at frequencies above 30 kHz, which shows up as failed AC voltage calibration on the annual recalibration cycle. We test all output functions including current to 20 A and AC voltage across the frequency range before listing any 5520A.

Yes, provided the instrument itself has a current NIST-traceable calibration certificate and its performance is within specification. ISO/IEC 17025 audits look at the calibration standard's uncertainty relative to the uncertainty required for the measurements being performed — they do not disqualify instruments based on age or original purchase date. A 5520A with a valid certificate showing in-spec performance is compliant. We offer NIST-traceable calibration of 5520A and 5522A units before sale on request.

The Datron 4910 (now Wavetek 4910) is an 8.5-digit DC voltage and resistance calibrator with lower DC uncertainty than the Fluke 5520A — the 4910 achieves ±1 ppm 24-hour DC voltage stability, used as a transfer standard for calibrating other voltage references. It does not generate AC voltage, current, or resistance as a calibrator; it is a precision DC voltage reference instrument. The Fluke 5520A is a full-function calibrator with broader capability but higher DC voltage uncertainty. Many ISO labs use both: the Datron/Wavetek as the DC voltage transfer standard and the Fluke as the full-function electrical calibrator.

Calibrating a 6.5-digit DMM requires a multifunction calibrator with uncertainties significantly below the DMM specifications. The Fluke 5520A is the standard choice for most 6.5-digit DMMs (Keysight 34461A, Keithley DMM7510). For the Keysight 3458A (8.5-digit), the Fluke 5720A or a Josephson voltage standard is required. The key parameter is DC voltage uncertainty at 10 V — the 5520A at ±9 ppm is adequate for most 6.5-digit DMMs but is inadequate as a primary standard for 8.5-digit DMMs.

Every calibration instrument we sell is evaluated before listing. Units that arrive with valid calibration certificates retain them in the listing. Units without current certificates are either calibrated by us before sale or listed as uncalibrated with that condition clearly noted and the price adjusted accordingly. We never sell a calibration instrument described as calibrated without a certificate to back it up. NIST-traceable calibration from our lab is available for most Fluke, Keysight, and Datron calibrators.