Many industrial systems rely on known pressure levels. In some cases, the pressure must be within an acceptable band and in others, a constant pressure is required.
Traditionally, the pressure was monitored using pressure gauges and pressure switches.
Today, Pressure Transmitters, or Pressure Transducers are used to pass the pressure information to an active device such as a PLC or VFD because a higher level of control is required.
Modern systems use a pressure transducer to convert pressure to an electrical signal which is monitored by electronic apparatus and either used to display the pressure, provide pressure feedback in a closed loop system, or provide operating pressure limits.
Pressure transducers can be used to monitor the pressure of gaseous or liquid mediums.
Many Irrigation systems are designed to operate at a constant pressure where the operating pressure is minimized as a means of reducing the hydraulic energy wastage in the system. The MPM489 pressure transducer is used in conjunction with a Variable Frequency Drive to control the pump speed such that the system pressure becomes independent of the flow.
In today’s focus on the planet, on energy usage and on resources usage, there is an increasing demand for improved efficiency and reduced wastage.
A common requirement in rural irrigation schemes, is a limit on the flow and total water usage. This requires flow management and commonly a flow meter like the MFE600E Flowmeter is used in conjunction with a speed control system.
Many bore hole pump failures can be attributed to poor water level control with standard float-less level probes set at too low a level. It is important that the minimum water level above the pump is controlled to comply with the NPSH rating of the pump. This is best done using a submersible pressure transducer MPM489W depth transducer installed with the riser pipe and incorporated into and depth control algorithm slowing the pump, or constricting the flow to ensure the NPSH remains in spec.
Water Supply systems
Town water systems operate on a “constant head” which means that the pressure at the consumer is constant. This is commonly achieved by using an elevated resevoir so that the system is gravity fed with the pressure set by the elevation of the resevoir.
In some towns, this is not a practical solution as there is no elevated areas that can be used and so the pressure is generated by electric pumps. Using an MPM489 pressure transmitter and VFD to control each pump, results in a constant pressure (head) in the system.
Grey water and effluent systems can be monitored and controlled using flush diaphram pressure transmitters.
The level of water in a resevoir or in a well is commonly measured by an MPM489W Level Transducer.