Daily Scale Verification

​Hi all​,

I am hoping someone out there could post a procedure for performing daily checks on scales with test masses.

At the moment our operators put the test mass on each corner of the scale and record that they have done this, however it doesn't look like we have a procedure to train them against.

Can anyone help me out?

Thanks

Who does the testing? Production or QA department? What I have done in the past is have the scale company come in, train the QA Manager then have the QA Manager train the technicians or production associates. As far as a written procedure you could write one fairly easily from the information given you from the scale company.

​Hi all​,

 

I am hoping someone out there could post a procedure for performing daily checks on scales with test masses.

 

At the moment our operators put the test mass on each corner of the scale and record that they have done this, however it doesn't look like we have a procedure to train them against.

 

Can anyone help me out?

 

Thanks

Hi rellie,

It's called daily calibration and usually falls within the overall instrument "Calibration", eg thermometers, balances, etc.

There are i think one or two generic "Procedures" on this forum for "Calibration" (I can recall posting one).

Regarding detail (Work Instruction ?)  you also need to decide things like acceptable tolerances between standard weights and indicated readings. this will maybe depend on what you are actually doing and the type of balance.

Dear Rellie,

Some 3rd party calibration laboratory (ISO 17025 certified) conducts seminar on calibration which you can apply on your in-house calibration of your measuring device. If you have not attended some training on calibration, these file may can help you.

regards,

redfox

calibration-principles-chapter1.pdf   415.36KB   535 downloads

Handbook_Calibration_en_co_46251.pdf   1.57MB   486 downloads

Hello rellie,

Another doc for scale calibration.

regards,

redfox

Scales Tolerance_05-chpt2-11-hb133-final.doc   472KB   639 downloads

Hi.

So it is the operators that do the check daily. The thing is we have the scales calibrated every 6 months and the verification done 2 yearly. I have spoke to the calibration company and the check on each of the four points is what they do every 6 months anyway.

I have not come across test mass checks before, but what I can gather is that the operators are checking that the scale reads the correct weight of the mass. They do not record anything. However after reading some literature, it look like it is a bit more to just moving the test mass around on the scale?

Thanks

Hi.

 

So it is the operators that do the check daily. The thing is we have the scales calibrated every 6 months and the verification done 2 yearly. I have spoke to the calibration company and the check on each of the four points is what they do every 6 months anyway.

 

I have not come across test mass checks before, but what I can gather is that the operators are checking that the scale reads the correct weight of the mass. They do not record anything. However after reading some literature, it look like it is a bit more to just moving the test mass around on the scale?

 

Thanks

Hi rellie,

It simply means that yr interpretation of the terminology "Calibration" is different to mine. As long as yr interpretation matches that of yr intended auditor (if any) there should be no problem.

Regardless of the test outcome and who does the testing, the actual readings should be recorded.  As others have said you need to establish tolerances which the 3rd party scale service provider can assist you with.  Keep in mind, the tolerances are dependent on any legal weighing you may be doing in the process.  In the US, the bureau of weights and measures has a guidebook which you can use.  I don't know what Australia agency has oversight of weights and measurements, but that would be the first stop to determine tolerances.

Auditors are typically satisfied if your calibration checks are within regulatory tolerances.  The work instruction for checking the scales is very simple and straight-forward given your description of the process in your facility.

Hi,

There's an easy way in doing daily verification of scales on the line. There are scales available that has a special function of "auto cal" and it works for you. You just have the set of calibrated test weights from a third party which will be used when performing an auto calibration function. The manual of the scales will give you the process of verification in house and we keep record of activity for documentation.

On an annual basis, we send the unit outside or hire a third party to do the calibration.

For BRC Standard ?

Woolworths ?

Hi All

I am the quality assurance manager in food manufacturing company. 

We are working with some weighing scales 5kg, 15 kg and 150 kg.

Annually we are doing calibration from outsourced accredited company for all scales.

But we need to start weight verification of scales weekly/monthly.

any SOP/WI which support to implement this successfully?

Please help me???

Sujith

Hello Sujith,

Please see attached file. It may help.

Daily Weighing Scale Verification procedure.docx   13.14KB   614 downloads

regards,

redfox

Hi All

 

I am the quality assurance manager in food manufacturing company. 

 

We are working with some weighing scales 5kg, 15 kg and 150 kg.

 

Annually we are doing calibration from outsourced accredited company for all scales.

 

But we need to start weight verification of scales weekly/monthly.

 

any SOP/WI which support to implement this successfully?

 

Please help me???

 

Sujith

Hi Sujith,

From previous posts, it likely depends on where on Earth you are.

This is the work instruction we use to train our QA employees.  It is set up as daily but can be modified for whatever frequency you need.  

Hello Sujith,

 

Please see attached file. It may help.

 

Daily Weighing Scale Verification procedure.docx

 

regards,

redfox

This is very helpful, but my question is what do you do when the weight you are recording is not what the standard weight (known) is. It only deviates by 0.01 which i know is small, but the form does not show any deviation. I just assumed a position for a QA tech to a QA mgr and this form was already laid out for me, but I have some questions with it.

Thanks in advance.

This is the work instruction we use to train our QA employees.  It is set up as daily but can be modified for whatever frequency you need.  

This is so very helpful. How was that tolerance determined? We perform these weight checks on a weekly basis and I just noticed there is a slight deviation from the test standard. It is small..like within 0.01 but i am unsure how to proceed. Thank you in advance for any information.

This is so very helpful. How was that tolerance determined? We perform these weight checks on a weekly basis and I just noticed there is a slight deviation from the test standard. It is small..like within 0.01 but i am unsure how to proceed. Thank you in advance for any information.

See Post 13 then Post 8.

IIRC the relevant Guidebook is posted elsewhere on this Forum.

good morning everyone, 

I recently started working for a new company. Every other company i have worked we have had daily calibrations on scales, freezer temperature, thermometers, ph machines etc. Here we usually just have an outside scale company come in every 6 months and calibrate our scales. Should i implement a daily scale calibration as well as a verification on the freezer temperatures and thermometers or will the annual check and wall thermometers be sufficient?

This is so very helpful. How was that tolerance determined? We perform these weight checks on a weekly basis and I just noticed there is a slight deviation from the test standard. It is small..like within 0.01 but i am unsure how to proceed. Thank you in advance for any information.

I suggest reading this over.  At least the parts that apply to your process.

https://www.nist.gov...ist-handbooks-0

good morning everyone, 

I recently started working for a new company. Every other company i have worked we have had daily calibrations on scales, freezer temperature, thermometers, ph machines etc. Here we usually just have an outside scale company come in every 6 months and calibrate our scales. Should i implement a daily scale calibration as well as a verification on the freezer temperatures and thermometers or will the annual check and wall thermometers be sufficient?

Do you mean daily checks / verification the equipment is measuring within acceptable tolerance?

In my view daily calibrations are unnecessary unless your "checks" or "verification" is outside of the tolerance on a regular basis.  Really, the calibration frequency is established by what's in the equipment literature, regulatory body (what they may dictate), and how you use the equipment.

I've been in facilities where the scales get "beat up" on a regular basis and have a contract with 3rd party to do monthly service on all scales, including calibration.  Other facilities, I've had the calibration annually because the equipment was never out of tolerance on the daily check and equipment well maintained.

Thermometers are the same way.  A lot of it depends on the type of thermometer, e.g. a dial thermometer is much more susceptible to vibration and going out of tolerance versus a mercury / alcohol type of thermometer.  In my experience the dial thermometers would be calibration checked far more regularly, such as weekly or monthly and the more stable type of thermometers calibration checked annually.

Almost forgot...the pH meter typically calibrated daily or multiple times per day depending on usage and how well it is maintained, as well as, what your calibrations yield (does the slope vary greatly from calibration to calibration?).

I suggest reading this over.  At least the parts that apply to your process.

 

https://www.nist.gov...ist-handbooks-0

 

 

 

Do you mean daily checks / verification the equipment is measuring within acceptable tolerance?

 

In my view daily calibrations are unnecessary unless your "checks" or "verification" is outside of the tolerance on a regular basis.  Really, the calibration frequency is established by what's in the equipment literature, regulatory body (what they may dictate), and how you use the equipment.

 

I've been in facilities where the scales get "beat up" on a regular basis and have a contract with 3rd party to do monthly service on all scales, including calibration.  Other facilities, I've had the calibration annually because the equipment was never out of tolerance on the daily check and equipment well maintained.

 

Thermometers are the same way.  A lot of it depends on the type of thermometer, e.g. a dial thermometer is much more susceptible to vibration and going out of tolerance versus a mercury / alcohol type of thermometer.  In my experience the dial thermometers would be calibration checked far more regularly, such as weekly or monthly and the more stable type of thermometers calibration checked annually.

 

Almost forgot...the pH meter typically calibrated daily or multiple times per day depending on usage and how well it is maintained, as well as, what your calibrations yield (does the slope vary greatly from calibration to calibration?).

yes, i meant daily checks, so if for the most part our equipment is well maintained and never have problems with our freezer temperatures then daily checks are unnecessary?

yes, i meant daily checks, so if for the most part our equipment is well maintained and never have problems with our freezer temperatures then daily checks are unnecessary?

The true answer...THAT DEPENDS.  What level of risk are you willing to have if your temperature go outside of the desired range?  Risk in terms of food safety and quality with the materials in the freezer.

Almost every place I've worked daily temperature logs are done.  The only place it wasn't done is where we had continuous temperature monitoring with alarm notification.  I could pull the data anytime from the system and review it.  Those temperature sensors were checked annually for calibration.