Replaced 4 wire 100 ohm and PT_100 function and do a direct temp measurement on the DMM

f28cf50b · Peter Jansweijer · 2278009c · f28cf50b
Commit f28cf50b authored Feb 22, 2018 by Peter Jansweijer
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Showing with 4 additions and 34 deletions

wr_serial.py sw/insitu_alpha/wr_serial.py +4 -34

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--- a/sw/insitu_alpha/wr_serial.py
+++ b/sw/insitu_alpha/wr_serial.py
@@ -239,36 +239,6 @@ def get_statusline(ser_slave):

  return(stat_lst)

-  
-############################################################################
-def pt_100(ohm):
-
-  """
-  Calculates the temperature for a given measured PT-100 resistance.
-
-    ohm      -- Ohmic value of the PT-100
-  """
-
-  # Rt = R0.(1 + A.t + B.t^2 + C.(t-100).t^3)
-  R0 = float(100.0)
-  A  = float(3.9083e-3)
-  B  = float(-5.7750e-7)
-  # C = -4,1430e-12 for t < 0 degrees / 0.0 for t >= 0 degrees
-  # For C = 0 =>
-  temp = (-R0 * A + (R0**2 * A**2 - 4 * R0 * B * (R0 - ohm))**0.5)/(2 * R0 * B)
-  return (temp)
-
-
-############################################################################
-def get_spool_temp(dmm):
-
-  """
-  Read the fiber spool temperature with the Digital Multimeter
-  """
-
-  ohm= float(dmm.ask("READ?"))
-  return(pt_100(ohm))
-

 ###############################################
 # Main
@@ -347,10 +317,10 @@ if __name__ == "__main__":
    print(dmm.ask("*IDN?"))
    # Returns 'Keysight Technologies,34465A,MY57501367,A.02.14-02.40-02.14-00.49-03-01'

-    # Configure for 4 wire resistance range 100 ohm
-    dmm.write("CONFigure:FRESistance 100")
+    # Configure for 4 wire temperature measurement
    dmm.write("SAMPle:COUNt 1")
-    #print("Fiber Spool temperature", get_spool_temp(dmm))
+    dmm.write("UNIT:TEMPerature C")
+    print("Fiber Spool temperature", float(dmm.ask("MEAS:TEMP? FRTD")))

  ser_slave = serial.Serial()

@@ -512,7 +482,7 @@ if __name__ == "__main__":
            crtt_mean = numpy.mean(crtt[(crtt_skip + 1):])     # skip first measurements

            if args.t != None:      # open and configue Digital Multimeter with attached PT100
-              spool_temp = get_spool_temp(dmm)
+              spool_temp =float(dmm.ask("MEAS:TEMP? FRTD"))

            print("sfp_channel: ", sfp_ch ,"itu_channel: ", ch ,"crtt avarage over "+str(crtt_measurement)+" measurments: "+str(crtt_mean)+" fiber-spool temp: "+str(spool_temp))
            data_file.write(str(sfp_ch)+", "+str(ch)+", "+str(wavelength)+", "+str(crtt_mean)+", "+str(curr_drxm)+", "+str(curr_drxs)+", "+str(spool_temp)+", "+str(curr_temp)+"\n")