Inhouse Calibration Plus TUS in accordance with AMS 2750 rev E?

[BizPro]

Hello!

Nadcap heat treating, AMS2750, and pyrometry in general is not only my expertise, it is my favorite special process.

1. YES! You can perform TUS (Temperature Uniformity Survey), equipment calibrations such as temp controllers, chart recorders, and timers in house...given you have the appropriate required calibrations for your standards used. Sensitivity is very easy to check once someone shows you how to do it (Fluke 724 or other multi-calibrator).
2. You will need ATP (approved test procedures) for how you perform TUS.
3. You will need to ensure that your standards are calibrated every three months (data logger and multi-calibrator).
4. You will need a data logger (data recording unit), calibrated thermocouples, and a multi-calibrator (Fluke 724). You may need a timer depending the Make and Model of your recorder (chart paper w/pens require a calibrated timer).
5. You will need diligent record keeping. In the top 10 findings for Nadcap Heat Treating (AC7102 Rev.F now), 6/7 of the findings are directly related to pyrometry and in my experience it is usually a test certification/record issue (not always).
6. You need to know the use of different types of thermocouples (ie: K, E, J, N, S, R, B and more) and permissible usage as required by AMS2750E.
7. Be aware of additional customer pyrometry requirements. Boeing and Lockheed are examples of primes that have more stringent requirements than AMS2750E. So often calibration companies will certify a SAT or a TUS to BAC5617 and unfortunately their paperwork (and their service) does not meet the Boeing requirements (thermocouples is one of those areas).
8. Hire an experienced consultant to perform an internal audit for you to AC7102 or have them do a gap assessment to see where you are at.
9. Don't forget you need calibration stickers!
10. Ensure you have a good understanding of AMS2750 and the Nadcap checklist along with any customer requirements. My professional experience is in Quality and Operations Management in the following areas: ISO 9001, AS9100, ISO 17025, Nadcap Heat Treat, Chemical Processing, Materials Testing, Welding, Conventional and Non-Conventional Machining. With that being said, I find the most challenging area with a lot of companies is AMS2750E and Nadcap Heat Treating.

This doesn't cover everything you need but should start you on the right track. You will need a good QA person to review all internally generated test certifications (hint - correction factors and offsets!).

 

[BizPro]

Shane and Others -

Type N is a good base metal T/C even though it cost more. Per AMS2750 -Type N may be calibrated as well in certain circumstances (expandable vs. non-expandable). Type K and E are never allowed to be re-calibrated per AMS 2750. They may be re-used IF and ONLY IF it is under 500F and you have OE (objective evidence) that you have implemented the U-Formula and follow it. This is per AMS 2750, BAC5617 has more stringent T/C requirements.

 

[TrivialSublime]

Just a helpful correction here. BAC 5621 is Boeings specification for Temperature Control of Processing of Materials (i.e. their Pyrometry spec). BAC 5617 looks to be a heat treat spec. I am sure it mentions BAC 5621 in applicable documents but that?s kind of a round about way of getting there.

Also if Boeing legacy product (Douglas) is going to be heat treated then that calls in DPS 1.700, Douglas' Pyrometry spec.

My recommendation on recorders would be digital to eliminate the whole paper chart thing (pens, paper, etc.) and have them linked into your internal internet server for storage and easy access to records. Disc space is cheap. In the long run the expense and time spent will save you money.

Honeywell makes a good product called EZtrend that comes with both controller and recorder built in with multiple channels.

Omega makes good handhelds that can be used for calibration and SAT. We use an SSI datalogger still going strong after 6 years.

My own opinion about the K and N thermocouple changes from AMS 2750 Rev C and Rev D. The rumor I heard was Boeing has issues with the K thermocouples (T/C) having reliability problems. When the spec rev?d to D we went to N and use Ks as control and record T/C and discard those after a year without recalibrating which is not allowed as you state.

The Ks hold up quite well and it?s a shame to have to scrap them but it makes life easier.

Just my two cents on that.

 

[hackyue]

Re: Calibration Plus TUS in accordance with AMS 2750 rev E

Hi,there Yes we are still Nadcap approved ,yes it is customer requiments,
we need to buy new equipment To do Temperature Uniformity Survey(TUS)as I this moment company from outside do this for us,we are looking for savings like I said,My question is Can WE DO IT INHOUSE

I don't think there is any problem about doing all the test in house.

All of our customers accept it.

And it saves much money, and the efficiency is better

 

[Mtvated]

My past and current employers have perform SAT and TUS in-house. It would be more flexible to schedule calibrations around production and very cost effective.

 

[sol49720]

You could rent your needed Fluke meter instead of purchasing one, analyse the use cost over time against purchase cost to determine what is best for your individual circumstance. Don't forget to pull your data from the furnace sensors from the furnace recorder, not from the data logger or you will not meet AMS 2750E 3.5.13.3.2. You are using the data logger to verify your furnace recording is correct and within calibration.

 

[dgriffith]

... Don't forget to pull your data from the furnace sensors from the furnace recorder, not from the data logger or you will not meet AMS 2750E 3.5.13.3.2. You are using the data logger to verify your furnace recording is correct and within calibration.

...not from the data logger... This must be a misprint. Why have a reference data logger to check the furnace data recorder if your not going to use the reference data. Likely you meant pull the data from both?

 

[MTProcessing]

I think he's referring to the requirement to capture data from the control thermocouple during a survey in addition to the data from the survey thermocouples. The survey thermocouples have to go through a separate datalogger. Some setups allow the survey logger to also capture the data from the control thermocouple, but this does not meet the requirement. The control thermocouple data must be captured through the normal control instrument.

Just one of the 2750 items that can make a person's head spin.

 

[dgriffith]

Thanks for the information on what happens in industry. Guess I lead a sheltered life in the lab...

 

[robanbieber]

Hi bwdreiko,
Actually the CL25 sure could be used as a secondary standard. You would have to have it calibrated to a primary standard if I remember correctly.
We had a NADCAP auditor ask us why we weren't doing that for our data logger and we strictly don't because I like having that unit being calibrated by the manufacturer.
That being said, you can use (double check AMS2750E, don't think that?s changed in regards to this) , we also use the CL25 for furnace Instrument calibrations.

I do not think the Omega CL25 could be used as a secondary standard instrument for calibrating your TUS dataloggers or sensors.. as ams2750E states that the required calibration accuracy is +/- 0.3F (+/-0.2C). The omega CL25 only has accuracy of +/- 0.5F... see attached three sheets for omega CL25 specs plus ams requirement table... am I missing something?
The CL25 could be used to calibrate the intruments on the oven or be used in the TUS or SAT but it could not be used to calibrate the TUS loggers or the sensors.... I am looking for an instrument that can meet those AMS specs that does not cost a fortune.. anybody have any suggestions?