Understanding the Functionality and Applications of Positive Displacement Flow Sensors

Positive displacement flow sensors, also known as PD flow meters, are a crucial component in a variety of industries, including oil and gas, chemical processing, and food and beverage. These devices are designed to measure the volume or flow rate of a fluid moving through a pipeline. They operate on the principle of repeatedly filling and emptying compartments of known volume with the fluid. The total flow is then calculated based on the number of times these compartments are filled and emptied.

The functionality of positive displacement flow sensors is based on their unique design and operation. The sensor consists of a chamber that obstructs the flow. Inside this chamber, there are rotating or reciprocating components known as rotors. As the fluid flows into the chamber, it pushes against the rotors, causing them to move or rotate. Each rotation corresponds to a specific volume of fluid. By counting the number of rotations, the sensor can accurately measure the volume of fluid that has passed through it.

One of the key advantages of positive displacement flow sensors is their high level of accuracy. Unlike other types of flow meters, PD flow sensors are not affected by changes in temperature, pressure, or viscosity of the fluid. This makes them ideal for measuring the flow of viscous fluids or fluids with varying physical properties. Moreover, they can handle a wide range of flow rates, from very low to very high, making them versatile for different applications.

Instrument model	FET-8920
Measurement range	Instantaneous flow	(0~2000)m3/h
	Accumulative flow	(0~99999999)m3
	Flow rate	(0.5~5)m/s
Resolution	0.001m3/h
Accuracy level	Less than 2.5% RS or 0.025m/s.whichever is the largest
Conductivity	>20μS/cm
(4~20)mA output	Number of channels	Single channel
	Technical features	Isolated,reversible,adjustable, meter/transmission dual mode
	Loop resistance	400Ω（Max）, DC 24V
	Transmission accuracy	±0.1mA
Control output	Number of channels	Single channel
	Electrical contact	Semiconductor photoelectric relay
	Load capacity	50mA（Max）, DC 30V
	Control mode	Instantaneous amount upper/lower limit alarm
Digital output	RS485(MODBUS protocol ),Impulse output1KHz
Working power	Power supply	DC 9~28V
source	Power Consumption	≤3.0W
	Diameter	DN40~DN300(can be customized)
Working environment	Temperature:(0~50) ℃; Relative humidity: ≤85%RH(none condensation)
Storage environment	Temperature:(-20~60) ℃; Relative humidity: ≤85%RH(none condensation)
Protection grade	IP65
Installation method	Insertion pipeline installation

Positive displacement flow sensors are used in a variety of applications due to their accuracy and versatility. In the oil and gas industry, they are used to measure the flow of crude oil, natural gas, and other petroleum products. Their high accuracy is crucial in these applications, as even a small error in measurement can result in significant financial loss.

In the chemical processing industry, PD flow sensors are used to measure the flow of various chemicals during the manufacturing process. Their ability to handle a wide range of flow rates and withstand harsh chemical environments makes them ideal for this application.

In the food and beverage industry, positive displacement flow sensors are used to measure the flow of liquids such as milk, beer, and soft drinks during the production process. Their ability to measure viscous fluids and maintain accuracy despite changes in temperature and pressure is particularly beneficial in these applications.

Model	NTU-1800 Online Turbidity Tester
Range	0-10/100/4000NTU or as required
Display	LCD
Unit	NTU
DPI	0.01
Accuracy	±5% FS
Repeatability	±1%
Power	≤3W
Power Supply	AC 85V-265V±10% 50/60Hz or
	DC 9~36V/0.5A
Working Environment	Ambient temperature:0～50℃;
	Relative humidity≤85%
Dimensions	160*80*135mm(Hanging) or 96*96mm(Embeded)
Communication	4~20mA and RS-485 communication (Modbus RTU)
Switched output	Three-way relay,capacity 250VAC/5A

In addition to these industries, positive displacement flow sensors are also used in water and wastewater treatment plants, pharmaceutical manufacturing, and many other applications where accurate flow measurement is critical.

In conclusion, positive displacement flow sensors are an essential tool in many industries due to their unique design and operation. Their ability to accurately measure the flow of a wide range of fluids under varying conditions makes them a versatile and reliable solution for many applications. As technology continues to advance, we can expect to see even more innovative uses for these remarkable devices.