3.3
Design
Figure 3: SFU-BF NI GL
1
Gas sampling tube
2
Filter housing
3
3 pneumatic lines (backflush, activa‐
tion of main valve, zero gas)
4
Output sample gas line
5
Input connection bundle (electrical
and pneumatic lines)
6
Filter element with rotary handle
The gas sampling unit consists of the following subassemblies:
•
Gas sampling tube:
°
Heated gas sampling tube:
°
Unheated maritime gas sampling tube
°
Optional: Pre-filter at the tip of the gas sampling tube
•
SFU in IP54 enclosure:
°
Heated filter housing with filter element
°
Weatherproof enclosure
The electrically heated filter housing is made of coated aluminum. The filter housing is
insulated by an aluminum housing lined with polyimide.
The weatherproof enclosure is made of glass fiber reinforced plastic (GRP).
Thermostatic control
The gas sampling unit is thermostatically controlled.
•
Heating control with Pt100 sensor and external heating control
•
Limit value monitoring in the controller of the measuring system
3.3.1
Gas sampling tube
The length of the gas sampling tube depends on the conditions at the sampling point.
The gas sampling tube is available for maritime applications in an unheated version.
Type and length of the gas sampling tube are described in the supplied system docu‐
mentation.
NOTE
The gas sampling tube is supplied pre-assembled.
PRODUCT DESCRIPTION
3
8023849/14SF/V1-1/2019-07 | SICK
O P E R A T I N G I N S T R U C T I O N S | SFU
11
Subject to change without notice
