1 connecting and configuring external reference, E-m-hg2-s-v2.1 – ROTRONIC Hygrogen2 User Manual
Page 36
E-M-HG2-S-V2.1
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
HygroGen2: Humidity and Temperature Generator
with AutoCal/AutoCal+, Remote Control and
Range Extensions options.
Instruction Manual
Instruction Manual for Software
Version 2.1
Document Type
Page 32 of 75
Document title
4.2 External MBW/RH Systems Calibration Reference (AutoCal+)
To reduce further measurement uncertainties that can be achieved with the HygroGen2, ROTRONIC has
worked with MBW (and its US affiliate company RH Systems), the world’s leading chilled mirror
manufacturer to integrate their products into the HygroGen2. Particularly well suited is the
MBW/RHS473 Dew Point Mirror, whose RP2 measuring head is designed to be directly inserted into the
working volume of the HygroGen2 and works across its full range. Other models can be connected via
the heated Swagelok sample ports on the rear of the instrument.
For an in-depth discussion on measurement uncertainty and the choice of calibration reference,
please see
. There is also an Application Note, published by ROTRONIC which can be
found via:
In order to calculate relative humidity (RH) from a dew point (chilled mirror) hygrometer, you also need
to make continuous temperature measurements. All MBW/RHS instruments have the ability to record
external temperature, the 473 with RP2 head combination has the temperature probe on the end of the
head.
Relative humidity is calculated on MBW/RHS instruments using the Sonntag/Hardy equation. The same
algorithm is implemented into the HygroGen2 (see
4.2.1 Connecting and Configuring External Reference
Please also refer to the instruction manual appropriate to your MBW/RHS external reference.
Please use an Aten UC-232A USB-RS232 serial adaptor to connect the chilled mirror to any of the
HygroGen2 USB ports. You will also need a male-female RS232 extension cable.
Make sure the MBW/RHS reference hygrometer is plugged in, turned on and is connected to the
HygroGen2 via the USB/RS232 serial adaptor.
Figure 21: MBW/RHS RP2 Measuring Head
© 2014; Rotronic AG
E-M-HG2-S-V2.1