Scientech H410 Vector - Manual (Page 29)

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Calibration without an Interface Module and H410 Indicator:
Note: Whenever a large aperture calorimeter is used without an indicator the interface module is
not used.
For this procedure you will need to make an adapter cable to go from the calorimeter’s DIN connector to the
DVM. The voltage output is on pin 1 of the DIN connector and should be connected to the positive side of the
DVM. Ground is on pin 3 and should be connected to the negative side. Pin 2 is not used. Refer to Figure 5.
A. Connect a DVM to the white jacks of the calorimeter. Refer to Figure 4.
B. Measure the resistance of the substitution heater making sure to subtract the resistance of the patch
cables from the total resistance measurement.
Note: When measuring the substitution heater resistance of a 200 mm calorimeter, R1 and R2
must be connected together in series.
Compare this resistance to Rc in the calibration data in the front of the manual. The two should agree
within 2%. If not, contact Scientech.
C. Calculate the voltage equivalent to laser power using the following formula:
V = (R
c
x C x W) 1/2
where:
V = voltage applied to the heater coil
R
c
= substitution heater resistance from step B
C = Cal coefficient 360401 = 1.018 360801 = 1.000
380401 = 0.974 380801 = 1.008
380402 = 1.024 380802 = 1.008
384UV5 = 1.021 388UV5 = 1.002
W = desired laser power in watts
D. Connect the DVM to the calorimeter’s DIN connector.
E. Apply the calculated voltage (V) to the electrical substitution heater.
F. Record the voltage reading of the DVM (V
c
).
G. Calculate the calorimeter’s output sensitivity (S) as follows:
S = V
c
/W
where:
S = calorimeter’s output sensitivity
V
c
= voltage output from the calorimeter in mV
W = desired laser power output.
The measured sensitivity should be ± 3 % of the calorimeters original sensitivity value.