NOVATECH CONTROLS 1635 PERCENT WATER VAPOUR ANALYSER
1.1 DESCRIPTION
The Novatech 1635 Percent Water Vapour Analyser is designed for measuring water vapour in drying and baking
applications, where the drying temperature is above the maximum limit of conventional relative humidity sensors
(typically 130-150°C) or a more robust sensor is preferred. The analyser signal can be used with a conventional
controller to improve the efficiency of industrial drying or baking applications, as well as to optimise the quality of the
product being dried or baked. There are seven basic types of installation for the 1635 analyser (see table below)
22 sensors Indirect 2 Zone n/a n/a
31 sensor Direct, Fixed O2 0.1 - 21.0%
0.1% interval n/a
4
1 sensor Direct Ref'g O2 n/a Ambient Cooled/
Refrig'd Dry
5
2 sensors Direct Fired n/a n/a
6
1 sensor Switched Dry O2 n/a Ambient Cooled/
Refrig'd Dry
7
1 sensor External Dry O2 n/a n/a
82 sensor Direct Fired c/w RH n/a n/a
Setup Step 27
Dry O2 Upd' Mode Setup Step 28
Update Period Setup Step 29
Update Duration Setup Step 30
Update Freeze Setup Step 31
Update Deviation
1n/an/an/an/an/a
2n/an/an/an/an/a
3n/an/an/an/an/a
4
n/an/an/an/an/a
5
Constant/Auto 0.1 - 99.9 hours
1
0.1 hour interval 5-300 minutes
1 minute interval 1-60 minutes
1 minute interval 0.1 - 21.0%
1
0.1% interval
6
Timed/Auto 0.1 - 99.9 hours
0.1 hour interval 5-300 minutes
1 minute interval 1-60 minutes
1 minute interval 0.1 - 21.0%
1
0.1% interval
7n/a n/a n/a n/a n/a
8n/an/an/an/an/a
Directly Fired,
External Dry O2 Input
Directly Fired,
Auto Operation of Cal 2 Solenoid
Directly Fired,
External Drier Temperature, 0-400 Deg C
Indirectly fired,
2 zones
Directly Fired,
Constant Combustion
Directly Fired,
Ambient Cooled/Refrigerated Process gas
on Probe Reference
Directly Fired,
Constant/Auto Operation of Sensor 2
1. Indirectly Heated Dryers and Ovens, 1 Zone
The in-situ probe measures the oxygen content within the drying chamber and calculations are performed to determine
how much of the air space is taken up by water vapour. For indirectly heated dryers or ovens, an oxygen probe and
analyser are all that is required. The oxygen probe uses ambient air as a reference gas.
2. Indirectly Heated Dryers and Ovens, 2 Zones
If the dryer or oven has two zones that you would like to measure the humidity level in, a 1635 analyser can be
configured to read both zones and independently display and transmit the for each zone on independent channels.
3. Directly Heated Dryers and Ovens with Constant Combustion
If the dryer or oven has a fixed combustion system (fixed firing rate), where the reduction of oxygen due to combustion
is constant, then a reference gas sensor may not be necessary to condition reference gas from within the dryer. The
dryer or oven oxygen level can be entered on the analyser keyboard. The percent water vapour can be measured by
gravimetric methods to calculate the correct reading.
August 2009
41635 Water Vapour Analyser
