I'm back again. I was just talking to the Director of Technical Services about clause 7.6 Control of Monitoring and Measurement Devices. I had mentioned it before and he was seeing what he could find out about testing and calibration devices to use on the multimeters from our service department. After finding out the price and man-hours that would be involved he suggested that we just replace the multimeters yearly with some cheap ones from Radio Shack to comply with the standard. Has anyone tried this before? Is this even something that we should consider as an option?

I'm back again. I was just talking to the Director of Technical Services about clause 7.6 Control of Monitoring and Measurement Devices. I had mentioned it before and he was seeing what he could find out about testing and calibration devices to use on the multimeters from our service department. After finding out the price and man-hours that would be involved he suggested that we just replace the multimeters yearly with some cheap ones from Radio Shack to comply with the standard. Has anyone tried this before? Is this even something that we should consider as an option?

How will you demonstrate that the new meters are properly calibrated?

He seems to be under the impression that they contain some documentation saying that they have been calibrated, but I'm trying to find out if that's the case. If they do, would that be acceptable?

He seems to be under the impression that they contain some documentation saying that they have been calibrated, but I'm trying to find out if that's the case. If they do, would that be acceptable?

No. Even expensive multimeters don't come with the sort of documentation required to assure that traceable calibration, with calculated uncertainties, has been done. Rather than buying equipment to do in-house calibration, you should look into having a qualified service do it for you. Most will do the calibration in your building, if that's what you prefer.

Thanks for the info Jim. You've been a big help.I'll start looking into a service for this. :agree1:

You're welcome.

Another issue that comes from constant replacement of gages for new ones, even if traceably certified, is that you lose any history associated with it. You can't prove, for example, that even though the gage was acceptable at purchase that it stayed within specifications during the period of its usage. This is one of the major functions of recalibration/recertification. Additionally, you lose the ability to monitor the gage's stability over time and use.

What are you using the multi-meters for? You may not need to calibrate them at all.

Are you making resistors and need to verify that a 100 ohm 5% resistor is between 95 and 105 ohms? If so, your meter is being used for verification of product and needs to be calibrated.

Are you using the meter to verify power is off to a machine, or troubleshoot, etc. If so, it is more of a tool and does not need to be calibrated.

Just because it has an indicator, needle or digital display does not mean it has to be calibrated. I had this arguement with an auditor over torque wrenches at a trucking company in their service department. The auditor tried to insist that they had to be calibrated. I pointed out the standard required gages used to verify product (or words to that effect) to be calibrated. It ended up having to be a call back to HQ for the auditor. I won. Now, when I worked with a company that sold and installed tires, they did have to calibrate them as the torque setting was part of the product they sold to the customer. If I buy tires, I want to know they are attached to my car properly. If I had a package delivered, I really don't care if the truck has tires as long as my package is ontime and not damaged.

What are you using the multi-meters for? You may not need to calibrate them at all.



Excellent point, Tom....my mind was wandering down the same path.

First step is to asses your need - what are you measuring? What accurancy do you need?

A unit from Radio Shack may be just the right thing for the job.

My company makes parts out of sheet metal. We cut and bend parts. One of the our "critical issues" for us is the angle of the bend.

For a while (a LONG while), we bought 4" precision squares at about $40 each...and THEN had to requalify them every year. Except that in the course of that year, almost all had been lost or damaged. We decided to cut our own out of stainless steel on our laser, and replace them each year. Now, our laser does not make a square that is as accurate as one made by Starrett, but that didn't matter. We make shelves and cabinets. We need accurate equipment to make our parts.....but the term "accurate" is releative to the work you are performing.

Hope this helps a bit.

I agree with the other posts, it depends on what you are using the meter for. In our shop, assembly of equipment, not all of our meters are calibrated. Many of our meters are used to check point to point wiring (contunuity). For items that we are setting voltages we use a calibrated meter.

Our Service Department does repair work on the Computers that we sell and the multimeters are being used to help identify what needs to be fixed.

Thanks for all the help everybody. I just talked to the Service Manager he said that he uses it to test contiuity and voltage to locate the problem but that he doesn't use it once the system is repaired. He checks whether or not it is still doing what the customer said it was doing when they brought it in.

What do you think, need for calibration or no? I'm leaning towards no right now since we use it to diagnose problems but not provide evidence of conformity.

Thanks for all the help everybody. I just talked to the Service Manager he said that he uses it to test contiuity and voltage to locate the problem but that he doesn't use it once the system is repaired. He checks whether or not it is still doing what the customer said it was doing when they brought it in.

What do you think, need for calibration or no? I'm leaning towards no right now since we use it to diagnose problems but not provide evidence of conformity.I don't think you need to calibrate, but be sure to identify the meters as not to be used for acceptance of product.

I second that you don't need to calibrate. Your quality check is functional, not a measurement. Spend the extra money on a good quality reliable meter and skip the calibration.

Thanks for the responses. That should help out a lot.:thanx:

Actually, you may need what is known as a limited cal.....that is, only certain functions/ranges are cal'd.....

To check continuity you typically seek less than an ohm or two and for voltage then check for some value. The short is not difficult, have a specific wire, say 6", 16 gauge and the meter should beep or otherwise show short, which for continuity is good. Voltage - if to see whether you are going to get bitten or fried, then have that cal'd. After all, even with a good meter, if it is not cal'd, I would not stick my hand into a circuit where that meter was used to read.....the meter could be wrong and if no cal, then there is no sufficient periodic check.

Just my thoughts.

Hershal