The speaker lineup for the Embedded Online Conference is pretty amazing! Sign up with promo code GANSSLE149 and wonderful things will happen like reversal of male pattern baldness, a guest spot on Teen Vogue magazine, and a boost of what JFK called "vim and vigor." It will also get you registered for $149 instead of the usual $290 fee.

The DMMCheck is no longer available. The company does make other calibration devices, though.

How accurate is your DMM? If you work for a decent-sized company they probably calibrate at least some of the test equipment every year. But many others never check calibration. Buy a meter off eBay and you have no idea if reads accurately.

I recently came across the Voltagestandard web site which offers a number of low-cost references and ordered one of their DMMCheck devices. The specs are amazing considering the price:

  • 5.000 volt output reference, accurate to 0.01% +/- 500 µV
  • 1.000 mA reference, accurate to 0.1% +/- 1 µA
  • Three 0.1% resistors: 1K, 10K and 100k

The unit runs off an included 9 V battery.

It comes with a calibration certificate, and its accuracy is guaranteed for six months. For the first two years recals are free (user pays shipping) and after that it's $5. The vendor checks each unit against an 8.5 digit DMM that is recalibrated every year.

Calibration certificate for the DMMCheck

DMMCheck calibration certificate

Output of the DMMCheck

The DMMCheck's 5 volt output

Obviously, this unit provides only a few fixed values and doesn't substitute sending your DMM to a cal lab, but at $35 (for 25 PPM resistors; add $4 for 10 PPM) it's a bargain for those who don't get regular meter calibrations.