Monitoring devices vs measuring devices

[jlzepol]

Hi guys, just one doubt. From IATF point of view is there any difference between monitoring devices and measuring devices? I mean, can I have some pressure indicators out of the calibration system? (For instance, some manometers installed in machinery).
Thank´s

 

[Miner]

Independent of IATF, the definition of monitor is "to observe, record, or detect (an operation or condition) with instruments that have no effect upon the operation or condition". Based on this a monitoring device is a device that, independent of a person, automatically takes measurements and typically records those measurements. A measurement device would be any device that requires the intervention of a person to take the measurement even if that intervention is simply to load/unload the device. I believe that the intent is not to treat the two categories as separate, but to ensure that both categories are covered by your system.

 

[John Predmore]

I work in aerospace, and have not looked at IATF 16949 in a decade. But I think the definitions derive from ISO 9000, which says
[3.11.3] monitoring is determining the status of a system, process, product or activity.
[3.11.4] measurement is a process to determine a value.

The difference in meaning I rely on is that measurement is quantitative, and monitoring can be non-quantitative, such as pass/fail, high/in-limits/low, etc.

One example of monitoring is a pressure regulator on the supply line to pneumatic equipment. There may be something that looks like a gauge with numbers on it; but we may not care whether air pressure is 60 psi or 55 or 65. Monitoring means we use the indicator to tell if air supply is on and the pressure is the same as it was yesterday, and for diagnostics when we suspect a leak.

A monitoring device which does not give numerical output may still need a certain level of accuracy and possibly be linked to a standard or some documented basis (7.1.5.1) when it is used for product conformity decisions. Otherwise when the indicator dial says pass how do we know it really is a pass?

 

[Ron Rompen]

I disagree (slightly) with Miner's interpretation - a monitoring device does not have to record measurements - an example being the manometer mentioned earlier.
However, for the sake of simplicity during an audit, and also to make it easier on yourself, be consistent. If you have SOME pressure gauges which are in the system, then have them ALL in the system.
If you choose not to have them in the system, have an email/memo somewhere that you can pull up and reference, stating your reason(s) why - 9001 and IATF are not always very clear in certain areas (like calibration) and leave it up to you to to decide what you calibrate, how often, and by what method. Having your own internal practices documented can be very useful.

 

[Miner]

I disagree (slightly) with Miner's interpretation - a monitoring device does not have to record measurements

We don't disagree. That is why I said typically, because there are definitely devices that do not record the measurements.

 

[Bev D]

Isn’t the appropriate distinction whether or not the thing is used for final acceptance of product? The definitions of monitoring and measuring aren’t as critical? I haven’t read IATF so I’m not sure about the specific requirements and documented definitions.

That said I always question why one wouldn’t want to calibrate any gauge used for monitoring processes or measuring product (or vice versa ) to reduce cost related to the manufacture of non conforming material.

 

[John Predmore]

Coincidentally, I posted yesterday a Venn Diagram illustration in an unconnected calibration thread to help explain what ISO/AS says in 7.1.5. I conclude that out of the entire universe of measuring and monitoring devices existing in an organization, the requirements of 7.1.5.1 only apply to those devices related to a product conformity decision, and only a subset of those, where traceability is required or deemed important by the organization, does the 7.1.5.2 requirement to calibrate, verify, or both, apply. That is how I parse 7.1.5. To @Bev D's point, the organization can choose to do more than what the quality standard requires, and that may be smart, but it is also wise to know what actions are required and which are at your election.

To @Ron Rompen's point, there is a requirement to document fitness of purpose for a M/M device involved in a product conformity decision (7.1.5.1.3) but no requirement to document why the organization thinks calibration and/or verification are not necessary. I chose to add a separate tab to my Calibration Register to document those decisions, and I apply a Calibration Not Required label to many of such devices, although labeling ("identification to determine status") is only required for M/M devices that fall inside 7.1.5.2.

 

[Ashland78]

I would like to suggest monitoring is to mean that you verify before using it. Not necessarily everyday but somehow with a standard. This would not need to be 'recorded' but part of the process.

Now if it is on the control plan with a specification that would certainly be a calibrated item.

If the gage passed calibration the first two calibration cycle, I would spread it out then. Meaning passed 2 - 12 month intervals. Then go to 16 month, if passed 2- 16 month then go to 24 months.