ACR Electronics SmartReader Plus Reference Manual page 87

4. Place the logger with sensor or EH-020A module into the jar containing the LiCl solution
(RH = 11%) overnight to eliminate any hysteresis effects.
5. Quickly insert the logger (or module) into the next solution by swapping the lids.
Transfers should always be made in the direction of higher RH conditions. The jar
should be well sealed. Allow at least two hours to get within three percent of the
equilibrium RH. Repeat for next solution.
6. Call up the graph on your computer using TrendReader software. The profile you see
should reflect the test you have just performed.
7. Zoom in on the section that relates to the 33% RH level in the test chamber. Use the
mouse to find the byte value recorded during the latter part of the minimum two hour test
portion (refer to step 5). Record this as the "bL" reading.
8. Zoom in on the section that relates to the 75% RH level in the test chamber. Again, use
the mouse to find the byte value recorded at the end of the minimum two hour test (refer
to step 5). Record this value as the "bH" reading.
9. Switch to the Setup window in TrendReader software.
10. Use the following equation to calculate the "Low" calibration adjustment value:
Low = (71 x b
11. For the "High" calibration adjustment value use the following equation:
High = 40 x (-74/ (b
12. Now enter the same values by revising the logger file and view the corrected graphs.
13. If the results are satisfactory, save the calibration changes to the logger (remember to set
the RH channel's equation number back to 71).
Copyright © 2010 ACR Systems Inc. All Rights Reserved.
Salt
MgCl
2
NaCl
- 145 x b ) / 296
L H
- b ) - 1)
H L
SmartReader Plus Data Logger
RH
33%
75%
78