The micro flow transmitter is a differential pressure transmitter with a built-in orifice plate. The built-in orifice plate converts the minute flow measured by the old year into a differential pressure signal, and then the differential pressure transmitter converts the DC current signal into 4~20mA. .
The difference between the micro flow transmitter and the ordinary differential pressure flow meter lies in the following aspects:
- The former is a sensor and a transmitter integrated, the latter is the sensor and the transmitter are separated;
- For high differential pressure at low flow rate, the former is suitable for 50mm pipe diameter (typically 10mm and 20mm), while the standard throttle device is only suitable for pipe diameters of 50mm and 50mm or more, otherwise it will occur during processing. difficult;
- The former uses the method of real-flow calibration to ensure the measurement accuracy, while the latter does not need to be calibrated if the standard throttle device is used;
- The former is knowledgeable and installed on horizontal pipelines, while the latter does not.
There are two types of micro flow transmitters: one is the high pressure chamber flowing through the differential pressure transmitter; the other is the high pressure chamber that does not flow through the differential pressure transmitter. For the former structure, since the flow rate through the high and low pressure chambers is equal to the flow rate through the throttle member, only when the flow rate is zero, the differential pressure measured by the differential pressure transmitter is different from the pressure difference across the throttle member. equal. When the flow rate is increased, the differential pressure measured by the differential pressure transmitter will be significantly higher than the pressure difference across the throttle member, resulting in measurement error.
The orifice plate built into the micro flow transmitter can have different inner diameters. For example, the EJA115 micro flow transmitter has six internal meridians with a range of from 0.0508 to 6.350 mm to meet different measurement requirements. Use the handheld terminal to set the upper differential pressure of the differential pressure transmitter to change the flowmeter’s range.