Section 6 Parameter Settings
59 FT722 & FT742 (RS485) – FF & PM Sensors – User Manual
6.4.2 AT.1: Query the Acoustic Temperature
$<listenerID>,AT?*<checksum><cr><lf>
$<talkerID>,AT=<temp>,<units>,<status>*<checksum>
<cr><lf>
$aa,AT=±xxx.x,c,c*hh<cr><lf>
Read only parameter that returns the current acoustic temperature reading
in the range:
-61.0°C to +95.1°C
-77.8°F to +203.2°F
212.2K to 368.3K
The acoustic temperature is output in degrees Celsius
The acoustic temperature is output.in degrees Fahrenheit
The acoustic temperature is output in Kelvin
The acoustic temperature reading is valid.
An acoustic temperature reading is being acquired. The output may not be
valid during this time.
Example 1
Query the latest acoustic temperature reading – a valid reading in degrees Celsius.
Query acoustic temperature
$WI,AT=+023.9,C,A*15<cr><lf>
Sensor response (being acquired)
Example 2
Query the latest acoustic temperature reading. A valid reading in Kelvin is being acquired.
Query acoustic temperature
$WI,AT=+297.2,K,V*0C<cr><lf>
The AT query command returns the current acoustic temperature reading in the selected units. An
acoustic temperature reading will be returned even if the sensor is in the process of trying to
acquire a valid reading. The acoustic temperature reading is filtered with a one minute time
constant by default.
The accuracy of the acoustic temperature reading may be affected by the relative humidity of the
air surrounding the sensor. See Section 2.9 for further details.
Caution: The acoustic temperature feature requires calibration at FT Technologies. If the sensor
has had a software upgrade to 7.5 (or above) then the data will be uncalibrated and may not
comply with the official specification.