Certain design peculiarities of thermoelectric power meters in the optical range

Conclusions

• 1. The design formulas thus obtained serve to calculate the conversion factor, the time constant, and the dynamic range of a dry thermoelectric meter of average optical powers.

• 2. The nonlinearity of the meter characteristic can be substantially reduced by selecting the required ratio between the heat conductance values.

• 3. The error due to the difference between the heat transfer processes can be reduced to 2–2.5% by providing an approximately uniform distribution of thermal conduction along the axis of the conical receiver and by making the thermal conduction of its walls sufficiently high.

• 4. The effect of the slow thermal relaxations of the meter casing can be substantially reduced by selecting a sufficiently large ratio of the casing mass to that of the receiver.

• 5. Thermoelectric meters of optical power in the range of 1 mW-1 W, which have a sufficiently massive casing (m ₂/m ₁>10³), do not require an additional thermostatic control.

• 6. The location of the thermocouple winding on the surface of massive metal components which have an adequate thermal contact with a monolithic metal casing serves to reduce the time constant of the meter and simplify its construction.