Yokogawa Extractive Oxygen Gas Analyzer TDLS220 - Manual (Page 45)

<6 BASIC OPERATION> 6-15
IM 11Y01B02-01E-A 4th Edition September 11, 2012-00
NON-PROCESS PATH LENGTH
This is the optical path length inside the laser & detect
measurement unit. Typical values would be 3.5” to 4” with the
default value to use at 3.75”. Note that this dimension will vary
between analyzers.
Contact Yokogawa if unsure.
NON-PROCESS PRESSURE
This is the pressure of the non-process gas. Typically,
this will be close to atmospheric pressure of 1.01BarA or
14.7PsiA. Check the actual operating conditions and enter the
appropriate value. Contact Yokogawa if unsure.
NON-PROCESS TEMPERATURE
This is the temperature of the non-process gas with two
modes of input:
ACTIVE AMBIENT - ambient gas temperature derived from
integral sensor on detector circuit with offset adjustment
(typically -18 deg C). Note this off-set is due to the internal
heat of the controller unit, where the detect board is located in
TDLS220
FIXED – manual input of fixed temperature value
NON-PROCESS CONCENTRATION
This is the concentration of the non-process measurement
gas. For Instrument Air purge gas, the typical value would be
20.9% O2.
If measuring CO in the process gas and the purge gas is
Instrument Air, then these parameters are not applicable
because the CO concentrations typically found in Instrument
Air are below practical detection limits.