To Calculate:
Window edge drift (WS) due to temperature change. (SM600, SM607 only. SM606 is temperature compensated)

Given:
The window edges will drift at the rate of 1.7% per 10°C. WE = window edge in question given as distance from sensor face in inches. TD = temperature shift in degrees Celsius

Formula:
(0.017 x TD x WE) / 10 = WS in inches

Example:
WE = 2 inches TD = 20°C

Calculation:
(0.017 x 20 x 2) / 10 = .068 inches

Note:
The speed of sound increases as the temperature rises therefore the window edges will appear to move toward the sensor as the temperature increases.