User Manual

6
Operation of Astral Calorimeters with a Digital Volt Meter:
The calorimeters may be used with any digital volt meter (DVM) capable of reading 5 volts full scale.
Connect the output of the calorimeter to the DVM.
Select the DC volts mode.
Direct the laser beam on to the absorbing surface of the calorimeter.
When the display of the DVM has stabilized (about 2 minutes), calculate the laser power using the formula:
W = V/S
where:
W = Laser power in watts
V = Voltage reading of the DVM in volts
S = Sensitivity of the calorimeter from page 2.
Operation of Astral Calorimeters with an Analog Chart Recorder:
Calorimeter Response:
The response of a calorimeter to a single pulse input as displayed by a chart recorder appears below.
Figure 3
The output voltage from a chart recorder can be converted to wattage at any time by:
W = V/S, W
i
= V
i
/S
V = Chart recorder voltage level in mV
S = Calorimeter sensitivity in mV/W
The total energy (E) in the pulse can be found by integrating the instantaneous wattage over time:
∞
E = ∫ W(t) dt
0
The following methods may be used to compute the total integrated energy: