Instruction manual

Appendix D. SDI-12 Sensor Support
selected, they will represent level of fresh water. The multiplier (slope) and
offset should be used to correct for relative density of water.
Sample number represents the number of values used to provide the output
value received by the datalogger. This output value is an average of the
samples.
The extended SDI-12 command used to configure output units is
aXCONFIG1=tt,pp,mmm.mm,ooo.oo! where a = the SDI-12 address of the
sensor, tt = temperature units, pp = measurement unit, mmm.mm = multiplier
(slope), and ooo.oo = offset.
Valid entries for tt (temperature) are:
0 = Celsius
1 = Fahrenheit
and valid entries for pp (pressure/level) are:
0 = psig
1 = kPa
2 = bar
3 = feet
4 = meter
5 = inch
6 = millimeter
Only SDI-12 instruction aM!, aM7!, and aM8! output the results obtained
when using the multiplier and offset. The multiplier and offset are only applied
to the pressure/level value, not to the temperature.
The extended SDI-12 command used to configure sample number is
aXCONFIG2=nnn!, where nnn is the number of samples that will be
measured to obtain the final output value, which is an average of the samples
taken. This value only applies to the aM8! command. The integration time is
a result of the number of samples selected. This value can be derived by
adding 2 s to the number of samples. For example, if nnn = 50, then 50
samples would be averaged. The integration time for this process is 50 plus 2,
or 52 s.
D-6