Pressure Gauge Calibration Uncertainty

[Sim0_x]

Hi guys & girls...

The company I am working for is looking to set up a calibrations lab, I was just wondering if anyone had any useful information I could use such as templates for procedures, certificates etc..

I've been reading a lot about MU and if anyoe has any xls templates with the calculations in I would be really greatful for them so I can learn how to do it.

Many thanks in advance.

S

 

[BradM]

Hello! Welcome to the Cove!

First, I would suggest you go to the file list. Follow the below link:

Post File Attachments Listing

You can type "uncertainty" as the key word. There are lots of threads and examples listed. It would be good for you to see them; as there are a lot of different approaches to measurement uncertainty.

Here is a link to one thread I put together for a Balance uncertainty

For uncertainty, in its simplest terms, you will add up all the potential contributors to uncertainty for a combined value. For example, you mentioned pressure gauge calibration. So your uncertainty budget may include uncertainty of your standard, any potential uncertainty due to environmental considerations, uncertainty if the gauge is affected by atmospheric pressure, uncertainty related to different personnel calibrating the instruments, etc.

When you mention setting up a calibration lab, my best suggestion would be to purchase a copy of the ISO 17025 standard. Whether your company chooses to pursue 17025 or not, the standard provides a really good basis on what you need to consider in setting up a lab.

I will say this... it's not for the feint of heart. Naw, seriously... there is a lot to setting up a good lab, and it's going to take money and management commitment. What you could do at a high level:

1. Purchase the standard. Sit down with management with the standard, and determine how serious the desire is.
2. If the desire is serious, then start at high level and estimate what resources it will take (personnel and money) to set up a good lab, write/maintain the quality system needed, and purchase/maintain the calibration standards.
3. If your management gives the go ahead, if you want to pursue 17025, I would contact the AB for 17025 and get quotations for your organization.

Hope that helps.

 

[Sim0_x]

Hi BradM,

Thanks for your comments, I do really appreicate them.

We already have 17025 (they had it before I joined, or maybe a different number. Its not really my department) but the current lab is set up for tensile testing etc..

Their plan was to purchase a Druck PV623 & DPI620 to calibrate the gauges, I have menitioned to them that at previous places I have worked before that they use a DWT but they have taken advice from another lab in nother country.

Do you think that the above equipment is appropriate for pressure gauge calibration?

Thanks

S

 

[BradM]

...

Their plan was to purchase a Druck PV623 & DPI620 to calibrate the gauges, I have menitioned to them that at previous places I have worked before that they use a DWT but they have taken advice from another lab in nother country.

Do you think that the above equipment is appropriate for pressure gauge calibration?

Thanks

S

it's hard to say. Druck makes excellent pressure standards; so does Fluke (Ruska line). But whether its a suitable standard will depend on the instruments you are going to be calibrating. In simple/basic terms, you will need a 3 to 1 or 4 to 1 accuracy ratio. You will want to calculate an uncertainty, but at least the rough cut accuracy ratio can let you know if you're in the ballpark for an acceptable standard.

 

[Sim0_x]

The equipment is pretty accurate looking at the specs.

I am unable to post links as of yet due to just joining, sorry.

 

[BradM]

The equipment is pretty accurate looking at the specs.

I am unable to post links as of yet due to just joining, sorry.

Yea... sorry about that. Spammers make it hard for all!

Anytime you need a legit link (like this one) inserted, feel free to send a note to any moderator or admin. We'll help.

*****
You could start building an uncertainty based on the standard and such. However, it will be difficult to complete it until you have some repeatability measurements among technicians; and potential contributors from environmental factors.