Yokogawa In-Situ Gas Analyzer TDLS200 User Manual
Page 37
37
IM11Y01B01-12E-A
1st Edition
•
Factory gain resistors on the detector board: R21 = ________; R22 = ________; R23 = ________.
PROCEDURE
1.
This procedure requires wearing a grounding strap connected to one of the grounding lugs of the
analyzer to prevent any electrostatic damage.
2.
Open the detector enclosure and put on a grounding strap.
3.
Identify the gain resistors R21, R22 and R23 on the detector board as shown in the photo above.
They are all plugged in sockets instead of being soldered, easy to be modified by a pair of small
pliers. The existing gain resistors have factory resistance values optimized on a calibration cell.
4.
[Optional] For a high-process-temperature application and if the current process temperature is
higher than 600°C, apply a multi-meter to measure the voltage across R21. If the measured
voltage absolute value is greater than 5V, change R21 to the 100Ω resistor from the resistor bag.
Keep the original R21 in the resistor bag as it can be used for future off-line calibration.
5.
Remove R22 and R23 from the detector board and replace them with the 11kΩ resistors from the
resistor bag. Please keep the original R22 and R23 in the resistor bag as they can be used for future
offline calibration.
6.
Optimize the analyzer alignment for both the launch and detector sides. Stop the alignment if
Detector Signal High fault activates.
7.
In the TruePeak user interface software, navigate to Advanced Menu (password) -> Configure ->
Laser Spectra & Control screen to check the raw detector signal. Write down the raw detector
signal
MAX
and
MIN
values for later use.
8.
Change R22 and R23 accordingly based on the current raw detector signal. Perform one item of the
following selections (a, b, or c).
a.
If Detector Signal High fault is active, change both R22 and R23 to the next smaller value
available in the resistor bag, and then go back to STEP 6. For example, if the current R22 and
R23 values are 11kΩ, the new R22 and R23 values should be 7.5kΩ. NOTE: please access
Active Alarm in the main user interface panel to check if Detector Signal High fault is active.
b.
If the raw detector signal is within requirement, remove R22 and R23 (and R21 if it was
changed to 100Ω in STEP 3) and cut their leads properly to fit the sockets tight and low, and
then go to STEP 9. NOTE: (1) for a low-process-temperature analyzer (with no capacitor on
R3), the raw detector signal is within requirement if
MAX
is between
0.0
and
4.0
; (2) for a
MAX
MIN