Remote Mou ti g Co figuratio - Heater Voltage Adjustme t
When a sensor s remote mounted, cons derat on must be g ven to the lengths of cable used and how t affects the
sensor heater voltage. D ffer ng lengths of cables w ll have vary ng amounts of res stance wh ch w ll sh ft the sensor
heater voltage. Because of th s, the heater voltage w ll need to be adjusted after n t al power up. Replacement of the
sensor w ll also requ re readjust ng the heater voltage. See sect on 3.6.2 for nstruct ons.
3.6 START UP
Upon complet on of all mechan cal mount ng and term nat on of all f eld w r ng, apply system power and observe
the follow ng normal cond t ons:
a) TP-524C “Fault” LED s off.
b) A temporary upscale read ng may occur as the sensor heats up. Th s upscale read ng w ll clear to “0”
ppm w th n 1-2 m nutes of turn-on, assum ng there s no gas n the area of the sensor.
Importa t Note:
A des ccant cap s attached to the sensor hous ng dur ng storage and sh pp ng. Th s prevents H20 from contact ng
the sensor f lm wh le t s off power, and thus helps to reta n the stab l ty of the factory span cal brat on. Remove
the des ccant cap 5~10 m nutes after apply ng power to the sensor, then nstall the weatherproof splashguard acces-
sory suppl ed w th your sensor.
Store the des ccant caps n a sealed conta ner ( .e., z p-lock bag) for future use. It s adv sed (but not mandatory) to
use the des ccant caps dur ng long per ods w thout power.
Note 1: If the d splay contrast needs adjustment, refer to sect on 3.10.
Note 2: If the sensor has been nstalled us ng the remote mount ng conf gurat on as descr bed n sect on 3.5.6, the
sensor heater voltage must be adjusted after n t al power up. If th s s the case, f rst adjust the heater voltage as
descr bed n sect on 3.6.2, then proceed w th the n t al operat on tests below (sect on 3.6.1).
Note 3: The 4~20mA output s gnal w ll be held at 4mA for the f rst two m nutes after power up.
3.6.1 I itial Operatio al Tests
Initial Ope ational Tests
After a warm up per od (at least 15 m nutes) has been allowed for, the sensor should be checked to ver fy sens t v ty
to H2S gas.
Mate ial Requi ements
* Detcon PN 6038 Threaded Cal brat on Adapter
* Span Gas 25 ppm H2S n a r at a controlled flow rate between 200 and 500 ml/m n(or 10 ppm for 0-20 ppm
range - see sect on 3.6.4 for more nformat on on ranges). NOTE: Do not use H2S and n trogen gas m xtures.
* Detcon PN 985-241100-321 In-L ne Hum d fy ng Tube
a) Connect the hum d fy ng tube between the cal gas cyl nder and the sensor hous ng. The hum d fy ng tube w ll
ntroduce amb ent a r relat ve hum d ty nto the Cal Gas as t passes through the tube.
b) Attach the cal brat on adapter to the threaded sensor hous ng. Apply a the test gas at a controlled flow rate of
200 to 500 ml/m (200ml/m n s the recommended flow). Observe that the LCD d splay ncreases to a level of
10-25 ppm or h gher (or 5-10 ppm for 0-20 ppm range).
c) Remove the test gas and observe that the LCD d splay decreases to “0 PPM H2S”.
In t al operat onal tests are complete. Detcon H2S gas sensors are pre-cal brated pr or to sh pment and w ll, n most
cases, not requ re s gn f cant adjustment on start up. However, t s recommended that a complete cal brat on test
and adjustment be performed 16 to 24 hours after power-up. Refer to cal brat on nstruct ons n later text.
3.6.2 Remote Mou t Heater Voltage Setup
If the sensor has been nstalled us ng the remote mount ng conf gurat on as descr bed n sect on 3.5.6, the sensor
heater voltage must be adjusted after n t al power up. Replacement of the sensor w ll also requ re readjust ng the
heater voltage. Follow the steps below to set the sensor heater voltage.
Detcon Model TP-524C Hydrogen Sulfide Sensor
PG.10
