Measuring principle thermal hot wire
Measuring range from 0.2 to 100 l/min
Output signal NPN - PNP - 1÷5V - 4÷20mA
Process connection 1/8" - 1/4" and fittings
Provided with a valve for regulating the flow
Temperature up to 50°C - Pressure up to 7.5 bar
The flowswitchesPFM series are designed to measure the flow of fluids such as dry air, N2, Ar, CO2.
Their particularity is to have a color display to highlight any irregular value.
Displaying the accumulated flow, the flow rate.
They are also mounting suitable for horizontal, vertical and panel.
There are versions available with a separate display.
The chip of the flow switch MEMS is constituted by a temperature sensor upstream (Ru) and by a temperature sensor downstream (Rd), arranged symmetrically to the center of a platinum thin-film heater (Rh), mounted on a membrane , and a sensor at room temperature (Ra) for measuring the temperature of the gas.
When the gas is static, the temperature distribution of the concentrated gas is uniform around Rh and Ru and Rd have the same resistance.
When the gas flows from the left side, alters the balance of the temperature distribution of the gas and the resistor Rd becomes stronger than that of Ru.
The difference in resistance between Ru and Rd is proportional to the velocity of the gas, in this way the misuraizone and analysis of resistance can show the direction of flow and the velocity of the gas.
Ra appears to compensate for the gas and / or the ambient temperature.
- Control of flow of N2 gas to prevent oxidation of the lead frame
- Flow indication Stored: shows the flow for the year or the remaining amount (N2 etc. ..) in a gas cylinder
- Suction control