SR50A Sonic Ranging Sensor
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formula is not applied, the distance values will not be accurate
for temperatures other than 0°C.
3.3 Temperature Compensation for SR50AT version
The SR50AT version of the sensor includes a temperature
sensor to compensate the speed of sound for variations in air
temperature. The temperature sensor is incorporated into the
SR50AT Cable as shown in Figure 1 SR50AT-CBL
Figure 1 SR50AT-CBL
By default the temperature correction will be on for RS-232
and RS-485 modes. For the SDI-12 output mode the
datalogger must include a measurement command that has
temperature in the output. Otherwise the internal temperature
correction will not be applied. The following “M” commands
automatically apply the temperature compensation to the
readings from the SR50AT:
M2, M3, M4, M7 and M8
(see section 3..4.3 for the complete list of SDI-12 commands).
Command M9 is used to obtain a temperature measurement
without a distance reading. The M9 command makes it
