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

E-M-HG2-S-V2.1