AirSafe –
Continuous dust monitoring
in ambient air

Monitoring of dust concentration in control system areas, silo areas, boiler houses or work stations.

  • The creation of dust explosion zones can be prevented.
  • Dust concentrations at work stations are safely monitored.
  • Possible dust escape from system parts is quickly detected.
  • AirSafe can be used as early detection for dust which could endanger the workplace.
  • Also for applications in zone 22 dust.

What do you want to do?


Triboelectric sensor technology from SWR has proven itself in thousands of applications for measuring dust concentrations in process systems.

AirSafe is a new measuring instrument which can monitor the dust concentration in ambient air, for example in control system areas, silo areas, boiler houses or work stations.

AirSafe monitors concentrations on the basis of pre-set limit values.

For example, to avoid the accumulation of dust in explosion zones or to detect unnoticed accumulation of dust from processes.

AirSafe can be used as early detection for dust which could endanger the workplace.


AirSafe consists of a flow duct and an integral triboelectric dust sensor.
A current of air is drawn through the duct at approximately 100 m3/h.
Dust particles, carried in the air current, passes the sensor, this generates a charge transfer, which is used as the measurement signal.
This signal is converted to electrical process outputs which could be used for display or control.

The AirSafe flow duct is 500 mm long and 100 x 100 mm square.
The integral dust sensor has a relay output which energises when the set limit value is exceeded.
The unit is supplied pre-calibrated.
The alert point is set to approximately 25 mg/m³ of dust.
The user can set his own alarm threshold.
This may be set within a range of approximately 5 mg/m³ to 150 mg/m³.
The alert point can be changed in steps of 5 mg by simply pressing a button.
As well as a contact closure output, the sensor also has an RS 485 output which can be connected to a wall mount or DIN rail mount transmitter.
The output from the transmitter is a standard 4 . . . 20 mA process output.
The transmitter also has a ModBus RTU RS 485 output which can also be used for connection to a PC.
By using the visualisation software, up to 10 measuring points can be displayed and saved and can be interfaced to other computer programs, e. g. Excel.

Mounting and Installation

AirSafe can be installed anywhere in a room.
Except of high ambient temperatures, there is no need to maintain distances from units or walls.

AirSafe can be wall-mounted using brackets provided.

Technical Data
Sensor Measured objects Solid particles in a gas stream
Particle size 0.3 µm or larger
Measurement range From 0.1 mg/m<sup>3</sup>
Ambient temperature – 20 . . . + 60 °C
Humidity 95 % RH (non condensing)
Measurement principle Triboelectric
Damping time 1 s
Output signals Relay output, either NC or NO
Dimensions 500 x 100 x 240 (L x W x H)
Housing material Aluminium
Protection type IP 65
Power supply 24 ± 10 % V DC
Rating Max. 10 W
Electrical connection Screw terminals
Weight 5.5 kg
Transmitter (DIN rail) Power supply 24 ± 10 % V DC
Power consumption 20 W / 24 VA
Protection type IP 40 to EN 60 529
Ambient operating temperature -10 … +45 °C
Dimensions 23 x 90 x 118 (W x H x D)
Weight Approx. 172 g
Connection terminals conductor cross-section 0.2 – 2.5 mm<sup>2</sup> [AWG 24-14]
Current output signal 4 … 20 mA (0 … 20 mA), load < 500 Ω
Switch output – measurement alarm Relay with switchover contact, max. 250 V AC, 1 A
Interface ModBus (RS 485)
Data backup Flash memory

Application Examples

Click on a desired application example to navigate to a detailed description.

Dust monitoring at spray dryer

Emergency shutdown with AirSafe

Plant protection – dust monitoring with AirSafe

Global Technology Systems

P.O. Box 799 Shalimar, FL 32579. USA
(850) 651-3388
[email protected] 


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