Flow monitor

Flow monitors in the series RVM/UM from Meister Stroemungstechnik are specially designed for applications in which the monitored flow limit value is much smaller than the normal operating flow. Thus, the smallest practicable switch-off point is 0.1 l/min, at a recommended maximum operating flow rate of 120 l/min. The device is specially constructed to attain a wide operating range at high switch accuracy and minimal pressure loss. At flow rates in the range of the desired limit value, the lower part of the measuring piston is closely fit into a cylindrically bored hole, so that the desired switch point can be precisely adjusted. The switch-off point, as well as the switch-on point is located in this range.
As volume flow increases, the measuring piston emerges from the cylindrically bored hole and provides a much larger cross-sectional area for the flow medium.  Through the installation of a spring, which returns the piston to its initial position, the flow monitor can be operated in any orientation. Electrical control is accomplished by equipping the piston with magnets, which energize a potential free, bistable reed contact housed separately along side the flow monitor body. The reed contact is completely sealed within the housing, whereby, depending on the connection used, (plug socket or cable), a protection class of IP65 or IP 67 may be attained. The compact design, robust construction, high pressure- and temperature resistance, allow these devices to be employed in the most demanding environments.
In the standard version, the flow monitor has a maximum operating temperature of 120 °C; the high temperature version is employable to 160 °C. Maximum operating pressure is 250 bar and 300 bar respectively. Switch contacts are available as normally open or change over contacts.
The switch points, specified by the customer, are factory set and tested, and can range from 0.1 l/min to 30 l/min. Switch points over 3 l/min have an accuracy of ±5 % of switch value. The accuracy under 3 l/min is ±0,1 l/min. The flow monitor is also available in an EX-version to comply with ATEX standards.