Scientech S310 Vector - Manual (Page 33)

33
C
ALIBRATION OF
L
ARGE
A
PERTURE
C
ALORIMETERS
U
SING
E
LECTRIC
S
UBSTITUTION
H
EATING
:
Electrical substitution heating is a standard feature of large aperture calorimeters.
Figure 6
Calibration with an Interface Module and S310 Indicator:
A. Connect a DVM to the white jacks of the calorimeter. Refer to Figure 6.
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 or 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. Remove the DVM. Connect a power supply to the white jacks and connect the DVM to monitor the
power supply.
D. Set up the indicator in the Watts Mode and the 30W range.
E. Remove the screws holding the interface module’s ID tag and remove the plate to expose the circuit
board. Refer to Figure 5.
F. Apply Vh volts, stated in the calibration data you received with the calorimeter, to the substitution
heater.
G. If needed, adjust the calibration trim pot, R4 on the calorimeter circuit board, until Wh Watts, from the
calibration data, is displayed by the indicator.
Calibration without an Interface Module and S310 Indicator:
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 6.
A. Connect a DVM to the white jacks of the calorimeter. Refer to Figure 5.
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 or 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