Vaisala HPP272 User Manual

More Information
‣
Understanding Relative Humidity and Relative Saturation (page 10)
‣
Measurement Data Registers (page 47)
‣
Configuration Registers (page 48)
‣
Connectivity to Vaisala Insight Software (page 12)
‣
Setting Probe in Analog or Digital Mode (page 23)
2.5.1 Understanding Relative Humidity and Relative Saturation
Water and hydrogen peroxide have a very similar molecular structure, and they both aect the
humidity of the air in which they are present. HPP272 measurement makes a
dierence
between the humidity caused by both H
2
O
2
vapor and water vapor, and the humidity caused
only by water vapor:
• Relative saturation is a parameter that indicates the humidity of the air caused by both
H
2
O
2
vapor and water vapor. When relative saturation reaches 100 %RS, the vapor
mixture starts to condense.
• Relative humidity is a parameter that indicates the humidity of the air caused only by
water vapor.
%RH%RS
00
100100
H
2
O
H
2
O
2
%RS %RH
0 0
100
100
H
2
O
1 2
Figure 2 Eect of H
2
O and H
2
O
2
on relative saturation (RS) and relative humidity (RH)
1
Space without H
2
O
2
vapor. When H
2
O
2
vapor is not present, relative saturation equals
relative humidity.
2 Same space with H
2
O
2
vapor introduced. Relative saturation is higher than relative
humidity.
During H
2
O
2
bio-decontamination processes, it is often important to monitor the possibility of
condensation. For this purpose, it is not enough to know the level of relative humidity (RH),
because RH only indicates the humidity caused by water vapor. The possibility of
condensation is
aected by the combined humidity of H
2
O
2
vapor and water vapor, which is
why you need to monitor relative saturation (RS).
HPP272 User Guide M211972EN-B
10

Vaisala HPP272 Specifications

General

Brand	Vaisala
Model	HPP272
Category	Measuring Instruments
Language	English