Performing a TUS on a Furnace used at One Temperature - AMS2750-E

[homersam]

Hello, I am just new here and am starting to work with AMS2750 rev E

I have a furnace to perform a TUS on it, oven is used at one temp. (121oC +/- 5oC)
Furnace I believe is class D type 3

question would I have to do any temperatures below this or above this temp.?
also there is an excess t/c in oven but no display-how is this checked?

I will probably be back here a few times making enquiries
any help would be much appreciated,

 

[dwperron]

If you are only having the oven qualified at a single point then you only need to perform the TUS at that point.

As for the "excess" thermocouple - what is it there for? If you are using it then it needs to be calibrated like any other thermocouple. If you are not using it, you might consider removing it to eliminate questions about it.

 

[bigqman]

I just learned: Temperature Uniformity Survey ( TUS )

 

[homersam]

Thanks for reply dwperron & bigqman

just a few more points

is it not necessary to perform TUS at upper & lower limits
ie 121oC nominal +/- 5oC, checked at 116oC & 126oC?

(would id plate on furnace then require calibrated and for use at 121oC only)
I thought id plate on furnace had to have temperature range marked on id plate, is 121oC only fine?

excess controlling t/c has no readout on control panel of furnace,
inside electrical panel excess controlling t/c is connected to block with three separate settings with three arrows pointing to numbers, looks like it is set to 155oC

I was going to check excess controller is working by inputting a temperature over 155oC from my calibrator and see if it shuts off the furnace, just for completeness

I checked another furnace over a year ago with colleague who was the expert,
that furnace was for use at 515oC one set point, but my colleague insisted on a TUS at 450oC, 515oC & 550oC with excess set at 560oC it all worked out ok as furnace was brand new and calibrated fine
I now don't see the point in doing extra checks if they are not necessary

I will probably have more questions later, thanks for your help

 

[dwperron]

is it not necessary to perform TUS at upper & lower limits
ie 121oC nominal +/- 5oC, checked at 116oC & 126oC?

Upper and lower limits are checked for temperature bands, such as an oven qualified for use from 175 to 350°F would be checked at the high and low limits (at least).

I thought id plate on furnace had to have temperature range marked on id plate, is 121oC only fine?

That would be the right thing to do if it is only qualified at 121°C

I was going to check excess controller is working by inputting a temperature over 155oC from my calibrator and see if it shuts off the furnace, just for completeness

If you are only using the probe for over temperature control it does not need to be calibrated. The shut off check is the right thing to do.

 

[homersam]

thanks again dwperron for reply

just looking again at the other furnace my colleague done a survey on a while back, I do remember something in AMS2750 about a temperature set point over 350oC that it needs a TUS carried out below the 350oC and one at set point in this case 515oC, does this look right or have I read it incorrectly?

or is one TUS at 515oC permissible to AMS2750 Rev E

 

[dwperron]

The oven your colleague surveyed sounds like it was done over a qualified temperature range, not a single point. The rules for that are as follows:

2750E section 3.5.6:
Periodic TUS temperatures shall be any temperature within each qualified operating range.
3.5.6.1 - For single operating ranges greater than 600°F (335°C), during each periodic test TUS temperatures shall be selected so that one temperature is within 300°F (170°C) of the maximum and another temperature is within 300°F of the minimum of the qualified operating range and there are no more than 600°F (335°C) increments in between.

If this were the initial TUS:
3.5.5.1 - Initial survey temperatures shall be the minimum and maximum of the qualified operating temperature range(s).
3.5.5.2 - Additional temperatures shall be added as required to ensure that no two adjacent survey temperatures are greater than 600°F (335°C) apart.

 

[homersam]

thanks again dwperron



this furnace is only used at one set point , ie 515oC +/- 8oC

so I am not sure why he chose to do a TUS at 450oC, 515oC & 550oC?
would one set point of 515oC be acceptable?

another question if I may
when I am doing the TUS I use paper forms that were set up years ago and manually write every temp. during survey (data logger DPR3000 records t/cs and controlling t/c )
I then go through data logger to find out min. /max temp at each set point and record this on our paper forms and highlight them on data logger print out, the "mid soak" values are also recorded manually on form, this takes a lot of time and one mistake and that's the one an auditor will pick up on
(Our data logger will print every 5 mins. but doesn't print at say 1.05, 1.15,1.25, any thing ending in a 5 so I have to watch time and hit "print" button at each time ending in a 5
Colleague before me has been used to filling in paper forms for years and he used to take them home to fill them in, he wasn't keen in upgrading


Are there newer data loggers/recorders available that would allow you to produce an electronic cal. report that would have min/max temp,ramp up, run time (30 mins.) etc. to satisfy AMS2750 E?

Can the newer data loggers/recorders be set up to perform SAT test reports
(our furnaces are done every fortnight)

My boss is interested in upgrading our old DPR3000 and some training for me and a new colleague could you recommend one or two newer data loggers/recorders so I may look them up,

 

[dwperron]

Honeywell, Partlow, and Eurotherm all have multiple products that might work for you. Attached are a couple of links to sites that may have some info that could help in knowing what to look for


http://www.eurotherm.com/working-with-ams2750e-and-ams2750d
https://www.honeywellprocess.com/library/channel-partner/Webinars/4-22-13-AMS2750E-Update.pdf

 

[Will White]

this furnace is only used at one set point , ie 515oC +/- 8oC

so I am not sure why he chose to do a TUS at 450oC, 515oC & 550oC?
would one set point of 515oC be acceptable?

The only reason to do more than one set point is if your furnace is operated at multiple temperatures. Since you run your production at only one temperature you only need to perform your TUS at that one test temp of 515C.

another question if I may
when I am doing the TUS I use paper forms that were set up years ago and manually write every temp. during survey (data logger DPR3000 records t/cs and controlling t/c )
I then go through data logger to find out min. /max temp at each set point and record this on our paper forms and highlight them on data logger print out, the "mid soak" values are also recorded manually on form, this takes a lot of time and one mistake and that's the one an auditor will pick up on
(Our data logger will print every 5 mins. but doesn't print at say 1.05, 1.15,1.25, any thing ending in a 5 so I have to watch time and hit "print" button at each time ending in a 5
Colleague before me has been used to filling in paper forms for years and he used to take them home to fill them in, he wasn't keen in upgrading

Your current system sounds like it is not capable of meeting the current requirements of 2750E. The shortest interval permitted for data capture is once every 2 minutes (see paragraph 3.5.13.3.2 of 2750E).

Are there newer data loggers/recorders available that would allow you to produce an electronic cal. report that would have min/max temp,ramp up, run time (30 mins.) etc. to satisfy AMS2750 E?

Can the newer data loggers/recorders be set up to perform SAT test reports
(our furnaces are done every fortnight)

My boss is interested in upgrading our old DPR3000 and some training for me and a new colleague could you recommend one or two newer data loggers/recorders so I may look them up,

The software packages I've found that automatically generate a TUS report are very expensive for what you get. The best way I've found to manage our data is through Excel. You can build your own macros and spreadsheets to manage the data and do your reporting.

I haven't encountered a data logger or software that will automatically generate a SAT report.

The electronic data loggers that we use are Yokogawa DX paperless chart recorders.