EW- Thermal Flow Meter Element


EW- Thermal Flow Meter Element
Externally Wound Platinum Heater/Sensor

Thermal flow meters measure fluid flow based upon the concept of convective heat transfer. There are two main types thermal flowmeters: Constant Temperature Differential Flowmeter and Constant Current Flowmeter.

Constant temperature differential flowmeter: Sensor 1 measures the gas temperature. Sensor 2 is heated to a constant temperature, maintaining a fixed ΔT between the two sensors. Flow is measured as a function of the power required to maintain the temperature of Sensor 2.

Constant current flowmeter: Sensor 1 measures the gas temperature. Sensor 2 is heated via a constant current. Flow across the heated sensor causes cooling. Flow is measured as a function of the temperature difference between the 2 sensors.
The EW-Thermal Flow Meter Element was specifically designed for use in fluid flow instruments, providing repeatable and accurate measurement.

Applications: The same EW element can be used as both a heater (thermal flow measurement principle) and a temperature sensor in flow measurement units that use the principle of constant temperature differential technology to measure flow rate.

Construction: A platinum coil is wound around a high-purity aluminum oxide ceramic core. The exterior is coated in glass to provide a mechanical and environmental seal. Shear force-resistant connection wires assure a secure termination to extension wire, bonding pads, etc.

Advantages: - Performance: The robust design provides consistent, reliable operation under harsh conditions over a wide operating range.
- On-demand design: Sensor Technology works with “on demand” products. We can manufacture a micro-heater according to each customer’s specification, providing a suitable element specifically designed for the application.
- Dimensional flexibility: Design and manufacturing flexibility allow external dimensions to be adapted to meet application requirements.
- Quality: Sensors are manufactured under strict process control, with custom-designed process equipment, to ensure the quality and consistency of the end-product.


The quality policy of Sensor Technology aims to increase its participation in the world market of platinum temperature sensors, offering the best solutions in care and products, through:

  • prompt service to its customers;

  • the continuous generation of profit to its shareholders;

  • reduction of costs;

  • continuous improvement of their processes;

  • the use of raw materials from qualified suppliers;

  • recognition and development of its employees.