MicroStep-MIS MSB780X1D - Compensation Sensor FAQ

MSB780(X) - User’s Guide
Table 7: Relative humidity dependence of MSB780 and MSB780X
Maximum value of pressure correction according to RH
Temperature Relative humidity Correction
-50
◦
C to 10
◦
C (0 to 100) [% RH] < 0.1 hPa
-50
◦
C to 23
◦
C (0 to 100) [% RH] < 0.2 hPa
-50
◦
C to 40
◦
C (0 to 80) [% RH] < 0.4 hPa
-50
◦
C to 60
◦
C (0 to 100) [% RH] < 1.2 hPa
• Unscrew 2 screws holding the compensation sensor and pull the sensor out from the
mainboard gently.
• Install a new compensation sensor in place of the old one.
• Fix the new compensation sensor using two screws.
• Reconnect the hoses to the compensation sensor.
• If you have MSB780X version with display, reconnect the display cable to the connector
on mainboard.
• Close the barometer lid.
4.4.2 Compensation sensor FAQ
- What is the purpose of compensation RH sensor?
The resonating pressure sensor is relying on composition of air (mixture of gases). Adding water
vapor to air changes the ratio of the gases relative amount in the composition. This causes very
slight differences in pressure reading (according to table 7, depending on temperature and RH).
The humidity sensor is used to compensate this systematic error based on known physical
dependencies.
- Does the barometer require dry air, or some desiccant cartridge at the pressure input?
The barometer is designed for use without special air conditioning like desiccant cartridges.
Compensation sensor compensates the effect of RH on pressure reading.
- How long does the compensation sensor last?
The compensation sensor should last more than 5 years. In conditions with very high humidity
and condensation we recommend to check the sensor more often.
- What happens, if the compensation sensor fails or indicates false readings?
The barometer additional error may appear if the compensation sensor does not work right. See
table 7 for ranges and limits.
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