A friend recently purchased a DMMCheck Plus and let me take it home for some testing. This device provides a known DC voltage, AC voltage, four resistances, four capacitances, four inductances, and two frequencies that you can compare your instruments against. This was a great chance to check the accuracy of my DMMs, 2 of which I acquired second-hand.

When is it useful? It outputs a single voltage and single current measurement. It will not test all the ranges of your multimeter.

DMMCheck Plus

DMMCheck Plus Calibration Certificate

The DMMCheck Plus’s calibration certificate shows its component values measured with the following calibrated equipment:

  • HP/Agilent/Keysight 3458A digital multimeter, 8.5 digit
  • Keysight 53220A locked to 10 MHz with Trimble GPSDO
  • BK Precision 891 LCR meter

The following information was provided for this DMMCheck Plus unit:

Measurement Value
Serial Number XBY16
Calibration Date 4/16/2024
Burn-In Duration (Hrs.) 1200
Calibration Temperature 21.3C/71F
DCV Temp. Coefficient +6uV/F

HP 34401A DMM HP 34401A DMM DC current measurement.

Test Procedure

The following test procedure was used to evaluate my three DMMs: a Fluke 101, Fluke 79 III, and an HP 34401A.

  1. The DMMCheck Plus was hooked up to 15V (the battery was low).
  2. The same 3ft test leads with mini-grabbers connected the DMMs to the DMMCheck Plus.
  3. The Fluke DMMs warmed up less than 5 minutes.
  4. The HP 34401A warmed up an hour-ish.
Measurement DMMCheckPlus Fluke 101 Fluke 79 III HP 34401A (front)
DC Voltage Reference 5.0000 Vdc 5.001 4.99 5.00009
AC Voltage Reference 4.999 Vac n/a (1) 5.02 4.99702
DC Current Source (1) 0.9998 mA dc n/a (2) 0.999 1.00010
AC Current Source (1) 1.000 mA ac n/a (2) 1.002 n/a (3)
Freq 1 Hz Oscillator 100.00376 Hz 99.9 100.0 100.004
Freq 2 Hz Oscillator 10.000376 kHz 9.99 10.00 10.0004
Freq 1 Hz duty cycle 50.010% 50.0 n/a (2) n/a (2)
Freq 2 Hz duty cycle 50.000% 50.1 n/a (2) n/a (2)
100 Ω Resistor 99.964 Ω 100.1 100.2 100.0725
1 kΩ Resistor 1.0000 kΩ 1.000 1.000 1.00014
10 kΩ Resistor 9.9986 KΩ 10.00 10.00 9.99963
100 kΩ Resistor 99.991 KΩ 100.0 99.7 100.0017
0.001 µF Capacitor 0.001042 µF 0.00110 0.00123 n/a (2)
0.01 µF Capacitor 0.01028 µF 0.01036 0.01037 n/a (2)
0.1 µF Capacitor 0.1002 µF 0.1009 0.1001 n/a (2)
1.0 µF Capacitor 1.035 µF 1.088 1.081 n/a (2)
1 µH Inductance 1.020 µH n/a (2) n/a (2) n/a (2)
10 µH Inductance 10.27 µH n/a (2) n/a (2) n/a (2)
100 µH Inductance 107.2 µH n/a (2) n/a (2) n/a (2)
1 mH Inductance 1.016 mH n/a (2) n/a (2) n/a (2)

(1) The Fluke 101 is not an RMS-reading voltmeter.

(2) Instrument not capable of this measurement.

(3) The lowest AC current range is 1 amp.

DMMCheck Plus Fluke 101 DC voltage measurement.