Quick Answer
DMM calibration at Prism uses a Fluke 5720A multi-function electrical calibrator as the reference standard. The DMM is tested for DC voltage (5 points), AC voltage (5 points at 50 Hz and 1 kHz), DC current (5 points), resistance (5 points), and frequency — with expanded measurement uncertainty of ±0.005% to ±0.1% depending on function and range.
Key Takeaways
- DMM calibration reference: Fluke 5720A multi-function calibrator (10 ppm accuracy), traceable to NPL India.
- Calibration covers: DC/AC voltage, DC/AC current, resistance, frequency, and continuity.
- AC voltage calibrated at 50 Hz (power frequency) and 1 kHz (for audio/instrumentation).
- Prism calibrates 3.5-digit to 6.5-digit DMMs from all major brands.
- NABL certificate includes readings, error, and expanded uncertainty per function and range.
DMM Functions Calibrated at Prism
| Function | Test Points | Typical Uncertainty (k=2) |
|---|---|---|
| DC Voltage | 100 mV, 1 V, 10 V, 100 V, 1000 V | ±0.005% of reading |
| AC Voltage (50 Hz) | 1 V, 10 V, 100 V, 750 V | ±0.02% of reading |
| DC Current | 10 µA, 1 mA, 10 mA, 100 mA, 1 A, 10 A | ±0.02% of reading |
| AC Current (50 Hz) | 1 mA, 100 mA, 1 A, 10 A | ±0.05% of reading |
| Resistance | 10 Ω, 100 Ω, 1 kΩ, 10 kΩ, 1 MΩ, 10 MΩ | ±0.01% of reading |
| Frequency | 50 Hz, 100 Hz, 1 kHz, 10 kHz | ±0.01% of reading |
| Capacitance | 100 pF, 1 nF, 10 nF, 1 µF, 100 µF | ±1% of reading |
DMM Brands We Calibrate
- Fluke (115, 117, 175, 177, 179, 287, 289, 8846A, 8808A)
- Hioki (DT4200, DT4500 series)
- Keysight / Agilent (34401A, 34461A, 34465A, U1231A)
- Keithley (2000, 2001, 2002 series)
- Kyoritsu (KEW series)
- Mastech (MS8229, MS8261A)
- UNI-T (UT55, UT61 series)
- RISHABH (Rish Multi)
- Metrel, Megger, Extech, Sanwa
Frequently Asked Questions
How accurate is the Fluke 5720A reference calibrator used at Prism?
The Fluke 5720A has DC voltage accuracy of 2.4 ppm of output + 0.5 ppm of range — approximately 10 ppm combined, well within the 4:1 TUR requirement for calibrating 40 ppm accuracy DMMs.
Does Prism calibrate True RMS multimeters?
Yes. Prism calibrates True RMS DMMs for AC voltage and current at 50 Hz and additional frequencies (400 Hz, 1 kHz) to verify the True RMS response.
Can Prism calibrate 6.5-digit bench multimeters?
Yes. Prism calibrates precision 6.5-digit bench multimeters (Keithley 2000, Agilent 34401A, Fluke 8846A) using the Fluke 5720A at its lowest uncertainty settings.
What is the fastest turnaround for DMM calibration at Prism?
Standard DMM calibration has a 24–48 hour turnaround. Same-day calibration is available on request for urgent production needs.
Does calibration include checking the battery and fuse of the DMM?
Yes. Prism includes a pre-calibration functional check covering battery level, all range positions, and fuse continuity as part of the calibration service.
Written by
Er. Parthiv Kinariwala
Managing Director · Prism Calibration Centre · NABL CC-2480 · Ahmedabad
Er. Parthiv Kinariwala founded Prism Calibration Centre in 2004 and has over 20 years of hands-on experience in calibration engineering, NABL accreditation, and industrial compliance. His team performs 10,000+ calibrations annually from the Vatva GIDC laboratory, serving 5000+ industries across Gujarat.
Prism Calibration Centre — Vatva GIDC, Ahmedabad
Prism Calibration Centre
F-101, Rudraksh Complex 2, Phase 3, GIDC Vatva, Near Jasoda Nagar Cross Road, Ahmedabad — 382445, Gujarat, India
Phone: +91 98245 26444
Email: info@prismcalibration.com
NABL: CC-2480 · ISO/IEC 17025:2017
Hours: Mon–Sat, 9:00 AM – 7:00 PM