Calibration and Standards – a Fluke

Lurking among my many and varied pieces of old and new test equipment are several “standards” including a calibrated DC volt meter, a calibrated amp meter, and a calibrated sinewave generator. My Icom IC-718 has a calibrated crystal oven so it too can serve as a high frequency standard source. With this reference hence its calibrated receiver, the 718 can tap into NIST frequency/time standards via WWV.

In among all of this, I do not have any calibrated resistance, inductance, or capacitance standards. Even used, these standards go for a significant cost.
How important are standards in a home lab? Well, not really all that important. But it’s nice to know if the volt meter is within specs.

I connected my Fluke 77-IV and a calibrated Weston 622 volt meter standard and fed them in parallel with a varying DC voltage. The Fluke with 2 decimals of accuracy and the Weston 622 seemed to match perfectly. The same was true for the Weston 50772 amp meter standard in series with the Fluke 77.

The Icom IC-718 was set to 10.000 kHz AM receiving WWV which was mixed in with the frequency reference standard. It was perfectly in tune with zero beat on the oscilloscope. This means the 718 along with the frequency standard are in calibration. Both of these use crystal synthesis to generate selected frequencies.

I also have AC volt and amp meter standards.

But again, this is not really that important. It’s just that I have this surplus laboratory equipment and calibration is something I can do with it.
Most of these meter standards are what I had for quite a few years. I obtained each piece either directly or through another person from a lab or company that maintained this equipment. These devices were kept in a climate controlled environment, and not in some garage, shed or barn. As for having it recalibrated, that’s a whole nother story.

Having these meters professionally certified would be prohibitively expensive. However – sometime in my past working career, I use to do programming for a testing laboratory. At lunch or after work – it was easy to use one of their standards to verify calibration. Later after taking another job and moving on from the lab, it was – go with a buddy to his place of employment and do a little after-work comparison with a company’s certified calibration standards. My stuff never drifted. It was and is always kept in my heated/air conditioned home, never in the basement.

You-know, I’m sure you’ve heard of the humorous so-called Y2K expiration dates on electrolytic and wax-paper capacitors. But, I have two radios that are still all original. The Zenith C845 sat on my aunt’s bedroom chest of drawers since it was purchased by my uncle in 1964. It is all original and was never kept in a basement or attic. The same is true for my Emerson 652 that came from Grandmother’s house in 1962 – which by the way was my first radio. The only capacitor that was replaced was the electrolytic – which I did in 1965. The rest of it is original from 1947.

The point here is, if these instruments are not subjected to abuse or adverse conditions, they will remain functioning and in calibration for a very long time.

S November 2018

P. S. With all of the spectator sports on a dozen or so cable channels, the vast mega social media, the 50 hour work weeks, and the driving of kids everywhere, who has time for all of this? I do. I hate sports, I have only real friends, I’ve been fortunate enough to have work I really enjoyed and only had to work at it for 40 hours a week with ample time off, and – I was not fortunate enough to have children – with whom I could pass on knowledge of the substantive wonders of life.