Possible areas of application
SIKA VE series electronic flow monitors are used to monitor flow rates with typical application areas such as:
- Protection for pumps against dry running
- Monitoring lubrication circuits
- Cooling and heating circuits
- Monitoring for leaks
The flow monitor is easily screwed into the process pipe directly via a connection thread. As the measuring probe is available in two different lengths, a wide range of pipe sizes and wall thicknesses are covered.
At the compact version VES the flow sensor and the corresponding switching transducer form a single unit. This means that flow can be monitored directly at the point of measurement.
The electronic flow monitor works on the principle of the detection of temperature differences. The cylindrical measuring probe contains two temperature sensors. These have optimum heat conducting contact with the medium and are thermally well insulated from each other. One sensor is heated with a constant electrical power while the other sensor is not heated and thus takes on the temperature of the medium. When the medium is not in motion the temperature difference between the two sensors stabilizes at a constant level.
The flowing medium cools down the heated sensor. The changing temperature difference between the two sensors depends on the velocity and is a parameter for monitoring the specified minimum flow rate. This signal is sent to a comparator which controls a transistor output signal.
With a potentiometer the output signal is set to the requested set point. When the flow rate fails to reach this limit the transistor activates the output signal. A six position LED array displays the proximity to the alarm point which has been specified.
|Output signal||PNP, open collector|
Material electronic housing
Ca. 2...15 s
|Response time||Ca. 1...13 s|
|Max. pressure rating||200 bar|
|Medium temperature||-20...85 °C|
|Process connection||G½ male|
|Degree of protection||IP67|
stainless steel 1.4571
|Electrical connection||4 pin sensor plug M12 x 1 according IEC 947-5-2|
|Set point range (coverage water: 1...150 cm/s; oil: 3...300 cm/s)|
Further details can be found in the datasheet.