Vaisala VaiNet RFL100 - Field checking using a reference instrument; Calibration and adjustment using HM40

5.4.5 Calibration and adjustment using MI70
• Vaisala MI70 Measurement Indicator
• Connection cable for MI70 Measurement Indicator (Vaisala item 219980SP)
• Reference environments for the desired calibration and adjustment points (see
Adjustment points and requirements (page 44))
• RFL100 data logger with the probe to be calibrated
Optional:
• MI70-compatible reference probe and connection cable
You can calibrate and adjust the probe of your RFL100 data logger in one or two points using
the MI70 indicator. You can also do the 1-point calibration so that you compare the reading of
the probe to any MI70-compatible Vaisala probe that provides the same measurement
parameter.
1. Disconnect the probe from the data logger.
2. Connect the probe to be calibrated to port I of the MI70 measurement indicator using the
connection cable.
3. If you want to calibrate by comparing to the reading of a reference probe, connect it to
port II of the MI70 indicator.
4. Turn on the MI70 indicator.
5. Start the adjustment sequence from Main menu > Functions > Adjustments. If you have
two probes connected, make sure to start the adjustment sequence for probe I.
6. MI70 notifies you that automatic power o is disabled during adjustment mode, select OK
to acknowledge.
7. Select RH or T parameter for adjustment and select OK. This procedure assumes you are
adjusting relative humidity, but the same principles apply for temperature adjustment.
8. Insert the probe to be calibrated in the reference environment. If you are calibrating
relative humidity using two reference environments, use the dry reference first. If you have
a reference probe, insert that in the same environment. If you are comparing against the
reading of a reference probe, you can also use the ambient condition as the reference
environment, as long as its conditions are stable.
9. Wait for the measurement to stabilize. You can follow the stabilization from the GRAPH
display. Select ADJUST when the reading is stabilized in the reference.
10. To perform the adjustment using one reference environment (1-point adjustment),
perform these steps:
a. Select 1-point adjustment > SELECT > OK.
b. When the measurement is stable, select READY.
c. Give the reference RH value by using the arrow buttons and select OK.
d. To confirm the adjustment, select YES. If you select NO, you return to the adjustment
mode display and no changes are made.
e. Continue from step 13.
RFL100 User Guide M211861EN-D
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