Temperature and digital calipers

Cause is stated in the first sentence of your post...

On a more serious note, though, one suspect is a bad solder joint on a printed circuit board. Open one up; if there's a PCB inside it, examine every solder joint under strong magnification, and see if you find any cracks.

"Michael Koblic" wrote in news:JQGOm.52137$ snipped-for-privacy@newsfe21.iad:

Not sure, but when my Mitutoyo caliper stopped reading reliably above a couple inches, it was because of dirt on the scale where I had been holding it. I gave it a wipe down with alcohol, and it was fine.

Doug White

mattathayde had written this in response to

------------------------------------- Michael Koblic wrote:

i have had nothing but pain and trouble from my digital calipers, they work fine unless i am really measuring something. i have given up on them since a good pair costs 150 bucks where i can get a decent pair of mechanical ones for less than 10 bucks... now if only i could find a pair from a place i am shopping at or ordering from and not have to waste a whole order and shipping on just calipers

-matt

##-----------------------------------------------## Delivered via

Your description makes it sound like a cold-temperature-related problem, which surprises me because my Harbor-Freight-type calipers work ok at 3 - 4 C (except for it being clumsy to operate the little buttons when wearing insulated gloves).

Try the third one, or better, all three of them in the same time frame and environmental conditions. Also, try zeroing the caliper when it is open about an inch or two and see how far it works each way, and test whether the metric scale has the same problem.

Maybe they are too cheap and you need to upgrade to superior HF quality ;) calipers. BTW, re low batteries, aside from the LCD blinking (to signal low battery) my calipers seem to work ok for several months with low batteries, even in the cold. (I keep ok batteries in several calipers, but for the less-frequently used ones change the batteries less often.)

Try a fresh battery and if this doesn't help, get in the habit of carrying it in your shirt pocket. Gerry :-)} London, Canada

If they suddenly start working, you have a data point.

--Winston

On Mon, 23 Nov 2009 17:40:36 -0800, the infamous "Michael Koblic" scrawled the following:

The small capacitors on the circuit boards can freeze and explode during cold weather (it happened on my sprinkler timer), so keep them in the house. Batteries can, too, can't they? I've never lived in those extreme climes so I don't have anecdotal evidence.

-- It is not because things are difficult that we do not dare; it is because we do not dare that they are difficult. -- Seneca

The main "likely cause" is they are cursed DIGITAL. Get a dial caliper and it'll work in any environment. :-) ...lew...

I wished. Fine grit and chips will kill a dial caliper.

It may not be temperature per se, but temp close to where RH condenses. Those calipers have some very high impedance CMOS circuitry. I've had Mitutoyo digital calipers do that, never had a problem with those from HF!

(...)

Say! I think you are on to something there, Don.

--Winston

Just get a regular old vernier caliper and learn to read it? (Magnifying glass optional depending on age :)

I would clean the edge of the calipers and see if the roller is slipping. Being cold the bearing may have enough drag to slip on the caliper.

All three are doing this. Cleaning the edges did not help. A quick blast with a hair-dryer did. I suspect the condensation theory is closest to the mark. It is interesting that the calipers will measure OK up to 2", it is only when you go past that that the error begins to show. I take it that this is because the first two inches of the scale are protected by the housing during storage.

It's not a big deal as long as one is aware of it.

As soon as I find one that reads to 0.001".

(...)

--Winston

But yes -- the magnifying glass does come in with older eyes.

Enjoy, DoN.

All of my vernier calipers read to 0.001" and some of them aren't what I'd call "Good". Magnifying glass is optional if your eyes come with built-in 5 dioptre magnification, it's one of the few benefits of short sightedness :-)

Mark Rand RTFM

Is the 2" point where you may have been holding it in your hand?. I have a Mitutoyo scale and if I hold it long enough at one point then travel the head across there then it will often flag an error, just leaving it for a minute or 2 will sort the problem. I assume it's moisture from my hand on the measuring surface cover.