Kobold AFS-G2 Operating Instructions Manual

Operating Instructions

for

Room Hygrostat

Model: AFS-G2

AFS-G2

page 2 AFS-G2 01/03

1. Contents

1. Contents........................................................................................................2

2. Note ..............................................................................................................3

3. Regulated Usage ..........................................................................................3

4. Operating Principle........................................................................................3

5. Instrument Inspection....................................................................................4

6. Mechanical Connection.................................................................................4

7. Electrical Connection ....................................................................................5

8. Operation ......................................................................................................6

9. Technical Data ..............................................................................................6

10. Order Codes .................................................................................................7

11. Maintenance .................................................................................................7

12. Dimensions ...................................................................................................8

13. Declaration of Conformance .........................................................................9

Manufactured and sold by:

Kobold Messring GmbH

Nordring 22-24

D-65719 Hofheim

Tel.: [phone]

Fax: [phone]

E-Mail: [e-mail]

Internet: www.kobold.com

AFS-G2

AFS-G2 01/03 page 3

2. Note

Please read and take note of these operating instructions before unpacking and
operating the unit, and follow the instructions precisely as described herein.
The devices are only to be used, maintained and serviced by persons familiar
with these operating instructions and with any applicable regulations concerning
procedural safety and accident prevention.
When installed in machines, EWG commissioning is prohibited until it is
established that the machine meets the general requirements of the guideline.

3. Regulated Usage

The AFS-G2 is to be installed only in the specified applications. Every usage
which exceeds the specifications is considered to be non-specified. Any damages
resulting therefrom are not the responsibility of the manufacturer. The user
assumes all risk for such usage. The application specifications include the
installation, start-up and service requirements specified by the manufacturer.

4. Operating Principle

The room Hygrostat AFS-G2 is a two-position controller for regulating relative
humidity. The moisture sensing element in the sensor is comprised of several
strips of plastic fabric, each with 90 fibers of 3 µm diameter. These plastic fibers
undergo a special process to acquire hygroscopic properties, meaning that they
will both absorb and release moisture. The molecular structure of the fibers
changes when they absorb water, giving rise to a measurable change in length.
The length of the plastic fibers is thus a measure of the relative humidity. The
swelling effect, acting primarily in longitudinal direction, is transferred over a
suitable lever system to a microswitch with an extremely small changeover
movement (hysteresis).

The measuring element reacts quickly and accurately to the change in humidity.
The setpoint is set with the setpoint button so that the microswitch is actuated by
the lever system when the humidity setpoint is reached.

The special treatment of the measuring element ensures that its hygroscopic
properties remain stable, so that sensitivity is maintained unless destroyed by an
external influence.

The harp-shaped measuring element is mounted inside the housing and should
be protected against entry of coarse dust, dirt and water. The Hygrostat is
designed for unpressurized systems.