Calibration Frequency for Rarely Used Gages

"Golly, Ken. I guess the rest of us don't think of batteries when we think of calibration. A change of batteries doesn't change calibration of any dimension measuring instrument."

Really...exactly how does one read a digital readout with dead batteries? How many of you change batteries on a regular basis? How many get their instruments from a tool crib attendant who gives fresh batteries when issued? How many have of you have battery replacement as part of your calibration/verification methods?

Maybe you should be thinking about it...

Ken K said:

"Golly, Ken. I guess the rest of us don't think of batteries when we think of calibration. A change of batteries doesn't change calibration of any dimension measuring instrument."

Really...exactly how does one read a digital readout with dead batteries? How many of you change batteries on a regular basis? How many get their instruments from a tool crib attendant who gives fresh batteries when issued? How many have of you have battery replacement as part of your calibration/verification methods?

Maybe you should be thinking about it...

Click to expand...

You read a digital readout without batteries the same way you do when you have your eyes closed.

When you want to read the readout, you open your eyes (or change the battery!)

I have made it a point to issue spare batteries with every battery-powered tool or instrument for past 20 years, including battery-powered screwdrivers and drills for maintenance folk. I sure don't want a $30/hour millwright wasting time getting a new battery for a nut driver when I have a $200/hour machine down that needs 100 bolts reinstalled after repair. Where available, we have rechargeable batteries and chargers. For disposable batteries, we maintain inventory just as we do for ballpoint pens, wipers, eyeglass and lens cleaners, spare lamps for optical comparators, microscopes, flashlights, and PowerPoint projectors, etc. That's pretty much what the MRO function of Purchasing is all about!

For crying out loud - our business is to PREVENT discrepancies, not whine about them!

I agree providing SPARE batteries with equipment is a good idea if it is a LONG trip to the tool crib and the company can't/won't afford to pay the employee 5 minutes to grab a battery.
But unless you company enjoys throwing out $2 (or more) batteries on a daily basis, that seems like a real waste to provide NEW batteries EVERY time a tool is issued.
Talk about potential for COST SAVINGS.
We have electric calipers for the entire shop (less than 20) and about 3 electric mic.
When the battery dies, they grab another gage and give the dead one to me.
If we have any in house I throw one in.
If not time to order.
Actually I have 2 dead batteries in 2 of 3 electric mics that are currently stored.
Guess what, I'm not putting new ones in until some one needs them!

Batteries???

My ruler and tape measure don't have any batteries

Manufacturers recommended calibration

If previous results indicate that an item has not been found to be out of calibration, is it acceptable to expand the calibration frequency past the manufacturers recommended calibration cycle or should we always follow the recommendation?

Yes, a recommendation is exactly that - a recommendation. It is not a mandate. Much depends on the frequency of use, the environment, the skill of the user, etc.

We have a vibration analyzer that has an OEM recommended "calibration frequency" of one year. However, we produce about 4 machines per year that require use of the device. Four times between calibration isn't much use, so we extended it to five (5) years.

Once again, compare benefit to risk. If there have been no problems, keep extending.

Absolutley....

...and if they are very rarely used, how about "To be calibrated before use"?

/Claes

Thanks for the feedback guys,

The items that I am mainly concerned with are light loss meters and pin gauge sets. We have reviewed the calibration records from our external calibration sources and determined that the tools in question have not been out of calibration at any time therefore, I am considering extending the calibration frequency from 1 to 2 years and possibly further depending upon future results.

mshell

Top end of interval?

We have a customer that says we need to set a top end of our interval adjustments. We're using a modified NCSL RP-1 adjustment frequency, with the multipliers adjusted to match our onsite calibration frequency. Has anyone else ever been required to set an upper limit on a quasi-statistically based frequency?

deniser,
We have never had a customer request this.....

Do they know what they are asking or is this some young engineer that does not have a clue? (Sorry, I do not mean to offend anyone)

We have has stipulated government spects but nothing more than that.

Cindy