7 replies to this topic

[chrisolson]

Hello!

 

I ran into an issue with getting our water activity meter calibrated this year. The company usually sends out a loaner for a charge while ours is being calibrated. Last year there was a 45 day waiting period, so I gave them a 2 month notice this year. Thier reply was we cant send anything out till the end of December at the earliest, and it will take 30+ days after that to get yours calibrated.

 

This company is the only one to work on the unit as they make it. My due date is the end of July for calibration. While I've never had this come up on an audit, could this be a problem?..........plus they raise their price 600 over last year and stated if I wanted it 2 weeks earlier......I could pay them an additional 550 to be put on the rush order list.

 

What water activity meters are you using and the calibration service used? It may be time for us to change companies?

 

Thanks in advance 

[mohamed ahmed yusuf]

I used this equipment before and unfortunatelly i had the same issue, but let me share my experience it could help you, 

1. Try to do internal claibration based on distalled water or one f the solutins you have, for distalled water, water activity shall be 1, by this you can claibrate your equipment and add it to your claibration plan, 

2. Search for one of the accredited 17025 service providers who can do calibration for this equipment, check the accreditation body in your country through this link 

https://ilac.org/sig...natory-search/ 

 

for other options, i don't have enough data about other equipments that could do better job but hopefully the information above could help you,

[GMO]

I can't recall whether it was this make / model of water activity meter we had but it might be worth getting a second machine.  The one thing I do remember was when I bought one c. 7 or 8 years ago, it was far cheaper than I expected.  

[chrisolson]

Thanks GMO, I thought of a second one but they both need to be calibrated yearly and that would put them on a 6 month cycle. Each cycle for calibration would be ruffly 2500 putting me at 5 grand a year in calibrations with shipping/charge/time. I'm more looking at changing machines and company. And who knows next year the water meter company may be out a year for calibration at this rate. yikes! lol

[G M]

We're also using Aqualab instruments, 4te and 3's.  We have many instruments though, so there are always 1-2 out for calibration and have enough on hand to keep things operating.

[GMO]

Thanks GMO, I thought of a second one but they both need to be calibrated yearly and that would put them on a 6 month cycle. Each cycle for calibration would be ruffly 2500 putting me at 5 grand a year in calibrations with shipping/charge/time. I'm more looking at changing machines and company. And who knows next year the water meter company may be out a year for calibration at this rate. yikes! lol

 

Absolutely.  I'd definitely look at a different machine.

But on reflection, I think we had calibrated standards we used to calibrate the machine in house.  I'm not that up to speed on Aw meters but if the standards have been produced to a manner which is traceable to national standards, would that not suffice?

[chrisolson]

GMO, From what I have read I have to have a third party calibration yearly to meet the BRC standard?

[Tony-C]

GMO, From what I have read I have to have a third party calibration yearly to meet the BRC standard?

 

Hi chrisolson,

 

For BRCGS Global Standard for Food Safety Issue 9 there are requirements for Calibration checks (6.4.2) and also for Reference measuring equipment (6.4.3). Having your instrument calibrated annually is a belt and braces approach that is quite common, in fact for pasteurisation for example there would be two calibrated thermometers on the pasteuriser to check the pasteurisation temperature and these thermometers would be cross-checked against a calibrated reference thermometer on a regular basis.

 

My approach to your Aw meters would be based on how critical the Aw value was to the safety and legality of the product.

 

See more details of BRCGS requirements below.

 

Calibration Checks in Clause 6.4.2:

All identified measuring devices, including new equipment, shall be checked and, where

necessary, adjusted:

• at a predetermined frequency, based on risk assessment

• to a defined method traceable to a recognised national or international standard where

possible.

Results shall be documented. Equipment shall be readable and be of a suitable accuracy for the measurements it is required to perform.

Clause 6.4.2 Guidance:

The site needs to establish the method by which the precision and accuracy of equipment is verified. This must include:

• a predefined check frequency, based on a risk assessment (e.g. historical reliability, nature of use, manufacturer’s recommendations)

• who is authorised to complete the checks (e.g. trained staff)

• the method to be used (which must, where possible, be traceable to a recognised standard,

e.g. use of a master calibration thermometer that has a certified test certificate traceable to a national standard).

Equipment must be of a suitable accuracy for the measurements it is required to perform. For example, where temperature is critical to the safety of a product (as in pasteurisation or the canning process), the measuring thermometer requires an accuracy of ±0.5°C, whereas a thermometer used to check vehicle temperatures may only need an accuracy of ±1°C.

 

Reference measuring equipment Clause 6.4.3:

Reference measuring equipment shall be calibrated and traceable to a recognised national or international standard and records maintained. The uncertainty of calibration shall be considered when equipment is used to assess critical limits.

Clause 6.4.3 Guidance:

All reference equipment (e.g. a master thermometer) must be calibrated and traceable to a national or international standard.

Where equipment is used to measure or monitor a critical limit, it is important that the tolerance (or uncertainty) of the calibration is considered. For example, if a thermometer

is required to measure a critical limit of 72°C, but the calibration shows an uncertainty

of 0.5°C, then a thermometer reading of exactly 72°C could in fact represent a true temperature of anywhere between 71.5 and 72.5°C (i.e. the temperature could be lower or higher than the critical limit). In this situation, to guarantee a minimum temperature of 72°C, it would be necessary for the reading on the thermometer to always be 72.5°C or higher.

Records must be kept.

 

Kind regards,

 

Tony