2500S

[Aaron]

Has anyone ever had a J action on the 2500 Humidity Generator? I've had mine short cycled to 90 days for about a year now and it still requires Temp alignment every interval.

[Old-Navy]

Our 2500S has had nothing BUT "J" actions.   Are you rushing through the temp cal?

[Aaron]

Not at all. It normally takes me at least a couple of days to run the temp checks because I'm working other items and having to cal and recheck the unit. After running the internal cal, the temp indications are within .01 or .02 at all points during re-verification.

I've called Thunder a couple of times since we got the unit and there have been some other reports of temp problems, even to the point of one unit being removed from service by the OWC. And looking at the history of the unit in the latest update, the interval has worked its way from a 12 to a 4, so I'm pretty confident that I'm not the only one experiencing a reliability problem.

Since yours seems to pass consistently, I think I'm going to try and get a new set of temp probes from Thunder.

[MIRCS]

Okay quick question here Aaron. Are you using the ITS90 CPIN for the calculations.

[Aaron]

No, I'm not aware of a CPIN for PRT Ratio_Temp calculations. I'm using an approved spreadsheet that I wrote to perform the calculations using the cal data and interpolation formulas provided with the PRT from AFPSL.

[MIRCS]

The CPIN is on the Disk that comes with the SPRT from AFPSL.

The CPIN number is 88M-ITS90SPRT/CAL-T001-00A Rev1.

If you can't find it just contact Jay Goletz @ AFMETCAl...he'll get out to you.

I did notice a difference on the results given in the CPIN and an approved Spreadsheet that we were using also.

And i have to adjust the temp probes about everyother cycle.

[Aaron]

Thanks for the info. I just talked to Jay and it looks like they started sending out the CPIN with the SPRT's after I received mine. I should get my next SPRT in a week or so.

Did you investigate what was causing the difference in results?

[MIRCS]

I did somewhat and seemed to be a difference of the inverses. Also some of the ITS90 constants had changed.

[Aaron]

Well, I just bumped my spreadsheet against the new CPIN at several points and found zero difference between the two. You may want to have a look at that spreadsheet again if you guys are still using it. I'm still going to use mine to print out my most commonly checked points.

[MIRCS]

We're not still using it. I use th CPIN only. Question, how are you able to use the list for the most commonly checked points? As the ratio from the 3458A is always changing each time you run to those points.

[Aaron]

I have my spreadsheet configured to calculate the ratio readings over a 3 degree span in .01 degree increments, the middle degree being the target. Then I check the table at some random mid-degree points using the formula, (or CPIN), to verify the results.

[MIRCS]

Undrstand that Aaron, I just like the punch in for the ratio...and get the temps from the CPIN.