Det-Tronics TXL Series Gas Transmitter - Manual (Page 13)

SHIELD WIRE TERMINATION
Terminate the cable shield wire at a single location only
— at the signal receiver or, for intrinsically safe installa-
tions, at the barrier. Leave the detector end of the
shield wire unterminated and insulated it from contact-
ing any terminal or other conductor. The shield must be
floating at the detector to provide proper EMI protection.
If unused, clip the shield wire off short and insulate it
within the detector housing to prevent it from accidental-
ly contacting the detector housing or any other conduc-
tor.
IMPORTANT
Be sure that all wiring terminations and cover
screws are properly tightened after installation is
complete.
OPERATING MODES
WARM-UP
Upon power-up, the digital display will indicate the
operating software version (e.g. “LSP1.00”), and will
then count down from 30 to zero, followed by a display
of the gas type and detected concentration (e.g. “H2S
0”), at which time the detector is in the normal operating
mode. It is recommended that the detector be allowed
to operate for a minimum of 1 hour after warm-up to
enable sensor stabilization before attempting calibration
or gas exposure testing.
NORMAL
The digital display will indicate the gas type and detect-
ed concentration in PPM (e.g. “H2S 0”).
FULL SCALE RANGE ADJUSTMENT
TXL Series gas detectors offer the ability to field-select
full scale measurement ranges other than the standard
factory default range. The procedure for selecting a dif-
ferent range requires removal of the cover from the
enclosure, with all field wiring and cable connectors
connected and power applied to the device.
Two pushbutton switches are located on the inside of
the detector cover assembly. These switches are identi-
fied as “mode” and “set”. To change the full scale
range of the TXL detector:
1. Press and release the mode switch. This places the
detector into the Calibration adjustment mode.
2. Press the mode switch a second time and hold for at
least 6 seconds. This places the detector into the
Span adjustment mode.
3. Press the set switch to select the desired full scale
range on the LCD readout on the detector faceplate.
4. Once the full scale range is set to the desired level,
press and release the mode switch. The detector will
return to normal operating mode with the full scale
range set to the new level.
5. The full scale range setting can be checked at any
time with the detector in normal operating mode by
repeating steps # 1, 2, and 4 above.
6. After selecting a new full scale range, it is highly rec-
ommended to also change the calibration gas con-
centration level to a level that is at or near the mid-
point of the new full scale measurement range.
7. After this has been completed, it is recommended to
perform calibration using a calibration gas that
matches the new calibration gas concentration set-
ting.
Table 11 shows the adjustment range, adjustment incre-
ment, and default setting for each TXL model.
11 95-8541 1.1