Scientech H410 Vector - Manual (Page 28)

28
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 5
Calibration with an Interface Module and H410 Indicator:
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 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. 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 4.
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.