12 replies to this topic

[Wian]

One of our CCP's is the water pressure used to rinse bottles before filling.  Pressure gauges are calibrated every year but one of the retailer standards require the following:

 

"All measuring equipment used to monitor critical control points must be checked for accuracy at the start of every shift as a minimum."

 

The pressure is recorded every hour and the production line automatically stops when the pressure drops below the critical limit. 

 

How would the accuracy of a pressure gauge be verified with every shift?

 

Thanks

Edited by Wian, 05 April 2022 - 12:05 PM.

[Charles.C]

One of our CCP's is the water pressure used to rinse bottles before filling.  Pressure gauges are calibrated every year but one of the retailer standards require the following:

 

"All measuring equipment used to monitor critical control points must be checked for accuracy at the start of every shift as a minimum."

 

The pressure is recorded every hour and the production line automatically stops when the pressure drops below the critical limit. 

 

How would the accuracy of a pressure gauge be verified with every shift?

 

Thanks

Do you have the capability to attach a "Master" calibrated gauge at same location area as current gauge ?

[Scampi]

with a calibrated pressure gauge-

 

https://www.fluke.co...ure-calibrators

[Wian]

Do you have the capability to attach a "Master" calibrated gauge at same location area as current gauge ?

What is the difference between a Master calibrated gauge and a calibrated gauge? I know the Master is used to calibrate other un-calibrated gauges, but the gauges we use are all calibrated.

[Scampi]

The Master would have an annual outside calibration certificate associate with it (where you send it out to a 3rd part to be recertified annually) and that is the one you use to verify all other calibrations against

[Wian]

The Master would have an annual outside calibration certificate associate with it (where you send it out to a 3rd part to be recertified annually) and that is the one you use to verify all other calibrations against

We don't do in-house calibration, our gauges are calibrated each year by sending them to a 3rd party, after which we receive a calibration certificate for them.

[Scampi]

BUT your customer is asking you to do in house verifications daily so if you want their business you're going to have to get a master to make them happy

[Wian]

BUT your customer is asking you to do in house verifications daily so if you want their business you're going to have to get a master to make them happy

As stated our gauges are Master gauges as per your definition.  

 

My question is how do i verify the accuracy of these "Master calibrated gauges" daily?

[beautiophile]

You keep one gauge in the cabinet as the only master and let the others become "slaves". An assumption is that if a gauge works a lot (a.k.a. daily), it's not a master. intuitively, one loses its reference reliability due to the deviation and degradation by working load.

[Charles.C]

As stated our gauges are Master gauges as per your definition.  

 

My question is how do i verify the accuracy of these "Master calibrated gauges" daily?

Hi Wian,

 

In addition to previous Post, IMEX (thermometers)  the "Master" instrument is typically of higher specification/capability than routine units. For example the link in Post3.

But also see my query in Post 2.

 

Presumably, if you had some simpler method to directly re-calibrate your gauges, eg with a "standard" pressure sample,  there would be no need for these subtleties. For example balances are daily calibrated with reference weights. It can also relate to the desired accuracy, for example raw materials stored in iced solution can often be adequately checked with a dial gauge calibrated directly against melting ice.

[Wian]

Hi Wian,

 

In addition to previous Post, IMEX (thermometers)  the "Master" instrument is typically of higher specification/capability than routine units. For example the link in Post3.

But also see my query in Post 2.

 

Presumably, if you had some simpler method to directly re-calibrate your gauges, eg with a "standard" pressure sample,  there would be no need for these subtleties. For example balances are daily calibrated with reference weights.

 

Maintenance suggested we split the connection point to make space for the "Master" & "Slave" with a valve separating the two so that when the operators needs to verify the accuracy they can turn the valve to get the reading from the "Master" to verify the "Slave", basically what you stated in post #2.

[Charles.C]

Maintenance suggested we split the connection point to make space for the "Master" & "Slave" with a valve separating the two so that when the operators needs to verify the accuracy they can turn the valve to get the reading from the "Master" to verify the "Slave", basically what you stated in post #2.

Hi Wian,

 

Not sure if  the valve (pressure drop?) may interfere (I suppose liquids [incompressible] are less difficult than gases (my experience)). I guess you could alternatively use a "tee" sampling point but this presumably needs a lot more work.

Hopefully, you don't have a large number of  pressure gauges.

 

PS - If not a CCP, you might have less difficulties.

Edited by Charles.C, 06 April 2022 - 09:09 AM.
edited

[Wian]

Hi Wian,

 

Not sure if  the valve (pressure drop?) may interfere. I guess you could alternatively use a "tee" sampling point but this presumably needs a lot more work.

Hopefully, you don't have a large number of  pressure gauges.

Yes, I meant like a "T" connection.