If you work in industry or business, you probably have your electronic test gear and multimeters calibrated regularly. If you’re an amateur you probably don’t. We don’t have a fancy calibrator at TOG which can cost 1000’s and need regular calibration in itself. We do however have a 2 Euro voltage reference based on an Analog Devices AD548 voltage reference. Checking some of the multimeters that we have around, and the results are surprising.
The reference outputs 2.5, 5. 7.5 and 10V. Now this is a bit of a crude test, because this little reference is not calibrated or traceable to any standard. If you assume however that the voltages it gives are “exact”, a 20 year old Fluke multimeter is reading almost perfectly . Some other multimeters that we checked are a bit off, but still not too bad. We’re going to check some of the ultra cheap meters that we have too.
Fluke 77: 2.499, 5.00, 7.50, 10.00
Standard ST-3343 Clamp Meter: 2.495, 5.01, 7.51, 10.02
Velleman DVM890: 2.47, 4.96, 7.44, 9.92