Vaisala VaiNet RFL100 User Manual page 47

• When adjusting RH, the first point requires a < 50% RH humidity reference, and the
second point must be > 50% RH. The difference between the two references must be at
least 30% RH.
• When adjusting T, the difference between the two references must be at least 30 °C (54
°F).
When comparison against a calibrated reference indicates that adjustment of
humidity measurement is necessary, Vaisala recommends adjusting in two points,
11 %RH and 75 %RH. These humidities can be produced using LiCl and NaCl salt
chambers of the Vaisala HMK15 Humidity Calibrator.
Adjustment of temperature measurement is typically not necessary.
5.4.3 Field checking using a reference instrument
You can perform a field check of the RFL100 using any humidity and temperature
measurement instrument with a display. Typically field checking is done with a recently
calibrated portable instrument.
1. Place the probe of the reference instrument (or the entire instrument) in the same
environment as the probe of the RFL100. The environment should be as stable as
possible.
2. Wait for 30 minutes for humidity and temperature to stabilize. Verify that measurements
are no longer changing at the end of the stabilization period.
3. Record the readings from both instruments.
5.4.4 Calibration and adjustment using HM40
• Vaisala HM40 Handheld Meter
• Connection cable for HM40 Handheld Meter (Vaisala item HMT120Z300)
• Reference environments for the desired calibration and adjustment points (see
Adjustment points and requirements (page
• RFL100 data logger with the probe to be calibrated
You can calibrate and adjust the probe of your RFL100 data logger in one or two points using
the HM40 handheld meter.
1. Disconnect the probe from the data logger.
2. Connect the probe to HM40 using the connection cable.
3. Turn on HM40 and check that measurements from the probe are displayed on the screen.
4. Select Menu > Settings > Time & Date and verify that the current time and date are set
correctly on the HM40. Correct them if needed. The current date will be automatically set
as the calibration date of the probe when adjustment is applied in
5. Select Menu > Calibration.
Chapter 5 – Maintenance
44))
step 13.
45