INVUE CR288 CONCENTRATION MONITOR
19
Installation and Use Manual | Entegris, Inc.
6. Select the
Sensor Calibration / Factory Calibration
tab.
7. Press
Get from Sensor
to copy the IoR@20 value
from the sensor to the Re-zero Reference IoR
field.
NOTE: This is useful when multiple sensors are
exposed to the same chemical.
8. Press
DI Water
to reset the Re-zero Reference
IoR to 1.333000.
9. Press
Re-zero Sensor
to reset the IoR@20 for the
sensor to the Re-zero Reference IoR value.
10. Press
Save Memory
.
11. Return to the
Data Graph
tab.
The IoR@20 should now be 1.33300 ±0.00001.
Initialize Sensor
Initializing performs dark field correction and
normalizes pixel brightness. See "Cleaning and
Re-initialization."
NOTE: Any sensor that was disassembled should be
re-initialized.
Slope Adjustment
The sensor is shipped from the factory with a generic
calibration curve. The calibration of the refractive
index can be improved when the refractive index
standards are known. Use this feature to change the
generic calibration curve to a specified calibration
curve. The values in the Factory Calibration table used
to calculate the IoR are modified by an amount
proportional to their difference from the Re-zero
reference IoR.
1. Confirm that the Slope Factor field reads 1.000000.
Edit if necessary.
2. Re-zero the sensor using a reference fluid, typically
DI water.
3. Input the refractive index value of a known fluid,
one similar to the typical system fluid, into the
Expected IoR@20
field.
4. Expose the sensor to the second fluid.
5. Press the
Calc New Slope
button.
Pixel position to Index of Refraction
The factory calibration table calculates concentration
by translating the sensor output into refractive index
values at defined pixel positions at a defined
temperature.
DIGITAL I/O TAB
Digital Outputs: Alarm
The DDU provides two 5 V (dc) digital output chan-
nels, on pins 19 and 20 of the terminal block. These
channels are used to activate alarms on an external
device if the concentration moves outside the
user-defined range.
Figure 25. Digital I / O tab.
NOTES:
• There will be no software indication of an alarm.
• The digital outputs can be set for each sensor, and
each sensor can control both channels.
• If alarms are set for multiple sensors, there is no
indication of which alarm is being activated.
• If two sensors have an alarm set for the same output
channel, both alarms are active on that channel.