Maintenance BDS 3960
Teledyne Analytical Instruments 48
3. After the sensor has been purged for at least two weeks and the
baseline is stable, monitor the oxygen reading and ambient
temperature over a minimum period of 24 hours.
Take the maximum and minimum oxygen readings, and the
maximum and minimum temperature readings.
4. Calculate the coefficient using the relation:
Coefficient = (O2 max - O2 min) ÷ (Temp max - Temp min)
For example:
In a 24 hour run:
O2 max = 3.55 ppb
O2 min = 1.75 ppb
Temp max = 24.5 degrees C.
Temp min = 22.1 degrees C.
Coefficient = (3.55-1.75)ppb ÷ (24.5-22.1) °C = 0.75 ppb/°C.
This value is currently set to zero, since the sensor is
temperature controlled and should be left at zero unless qualified
personnel give instructions to change it.
4.3.2.4 SET DEFAULTS
The Set Defaults button will reset all parameters in the software,
such as calibration, alarm and range settings, Filter, Gas Factor,
temperature coefficient, etc. to their factory default values. Some of the
default values are listed below:
Table 4-2: Parameter Default Values
Parameter Default Value
Zero Offset 0
Span Gas 8.00 PPM
SpanFactor 24.42 (Default span factor =
100000 ppb/ 4095 ADC counts)