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IRT Calibration with MET/CAL

Has anyone had any experience writing MET/CAL procedures for Infrared Thermometers using the Fluke 4180 & 4181? Would be greatful for any tips, info, code examples...

Thanks in advance to anyone who can help.

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Luc Claeys

I use the Fluke 4181 manual and have made Manual MET/CAL datasheets.

I don't think using MET/CAL Runtime is a good option since it will take time to perform 3 to 5 testpoints.

Also the MET/CAL license will be in use for a long time.....

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Matthew Heathwood

Thanks for the reply, and I agree with your approach.

Edit: just checking all angles.

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Chad D.

Hello Matthew, there is definitely merit to Luc's point.  It can take a while to stabilize each temperature point, making batch calibrations very attractive.

 
I haven't written this type of MET/CAL procedure before, but I did just write a test case to show how the 4180/4181 can be controlled via RS-232.  I made it fairly elaborate so that you could use whichever sections you like for your needs.  I recommend running the test case in the Editor's Debug Mode so you can see what it is doing.
 
Once a new set point is selected, the procedure enters a stability checking loop that updates every second.  For each iteration of this loop, MET/CAL reports the current apparent temperature and heater duty cycle via the HEAD -2 FSC.  The loop will only exit once the 418x reports a stable condition.  The procedure then beeps via the computer speakers to let the operator know that the 418x is stable at the requested set point.
 
For a normal UUT verification procedure, I would recommend placing a variant of this test case within a subprocedure, then pass it the required information via global named variables (like @SetPoint).  This way, you can reuse the stability check routine for each test point, across multiple main procedures.  Once the stability routine exits, your calling procedure could prompt the operator to take a reading and type in the result, and then evaluate the result using EVAL or MEMCX.
 
 1.001 PORT [@4180][P9600,N,8,1,N][TERM CR][OTERM CR] # Clear the status registers. 1.002 PORT [@4180]*CLS # Read the display temperature units. 1.003 PORT [@4180]UNIT:TEMP?[I$] 1.004 MATH Unit = "deg" & MEM2 1.005 DO 1.006 MEMI Enter the desired temperature set point in [V Unit]: 1.007 MATH SetPoint = MEM 1.008 HEAD TEMPERATURE SET POINT: [V SetPoint] [V Unit] # Set the control set-point as a real value with acceptance limits based # on the model. 1.009 PORT [@4180]SOUR:SPO [V SetPoint] 1.010 DO 1.011 WAIT [D1000] # Read and report the apparent temperature. 1.012 PORT [@4180]SOUR:SENS:DATA?[I] 1.013 MATH Temp = MEM # Returns the current main zone heater duty cycle in percent. 1.014 PORT [@4180]OUTP:DATA?[I] 1.015 MATH Duty = MEM 1.016 HEAD -2 Apparent Temp: [V Temp], Heater Duty Cycle: [V Duty]% # Read the temperature stability test results. Stable = 1; Unstable = 0 1.017 PORT [@4180]SOUR:STAB:TEST?[I] 1.018 UNTIL MEM 1.019 HEAD -2 # Read the IR emissivity setting. 1.020 PORT [@4180]SOUR:EMIS?[I] 1.021 MATH Emissivity = MEM # Read the control temperature stability 1.022 PORT [@4180]SOUR:STAB:DAT?[I] 1.023 MATH Stability = MEM 1.024 PORT [@4180]SOUR:SENS:DATA?[I] 1.025 MATH Apparent = MEM 1.026 OPBR -z Temperature set point has been achieved, with 1.026 OPBR stability. 1.026 OPBR 1.026 OPBR Set Point = [V SetPoint] [V Unit] 1.026 OPBR Apparent Temperature = [V Apparent] [V Unit] 1.026 OPBR Control Stability = [V Stability] [V Unit] 1.026 OPBR Emissivity Setting = [V Emissivity] 1.026 OPBR 1.026 OPBR Set another point? 1.026 OPBR [7][D250][7][D250][7][D250][7][D250][7] 1.027 UNTIL NOT(MEM1) 1.028 HEAD 1.029 END
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Matthew Heathwood

Hey Chad, thanks for the code. I'll be running it though the debuger and do my best to understand it. I am learning as I go. You mentioned batch calibrations being attractive here and I agree. At the risk of biting off more than I can chew, I have to ask, is there a way to run multiple calibrations (multiple UUT's) at the same time? Is that a MET/CAL feature? Or would it  in the procedure? Thanks for your help.

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Chad D.

Hi Matthew, MET/CAL supports only a single UUT per run.

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