Thermal dispersion flow switch is a precise flow sensing device, whose movement principle is heat diffusion. The probe consists of two temperature sensors. One sensor measures the temperature of the fluid when the probe is immersed. The other sensor is heated by a constant power. This creates a temperature difference between two sensors.
Temperature difference is an inverse ratio to the flow velocity. The probe and housing are made by stainless steel or engineering plastic.
This creates a temperature difference between two sensors. Temperature difference is an inverse ratio to the flow velocity. The probe and housing are made by stainless steel or engineering plastic.

Specification

1. Flow velocity: 1~150 cm/s (water), 3~300 cm/s(oil) or, water: 1~70 cm/s, oil: 2~100 cm/s

2. Warm-up time: 15 sec. (approximate)

3. Operation temperature:-4⁰F~176⁰F (-20⁰C~80⁰C)

4. Ambient temp: -4⁰F~176⁰F (-20⁰C~80⁰C)

5. Operation pressure: 100 bar

6. Housing rating: IP67

7. Enclosure material/rating: Aluminum / Ex d IICT6

8. Wetted materia: 304SS

9. Supply voltage: 24Vdc A 20%

10. Output: Open collector---NPN / PNP, 400 mA max. (with current limiting).

Relay--- 1A/30Vdc, 0.3A/125Vac (NO or NC), 5A/250Vac max. (NO)

NOIKE explosion-proof type flow switch ：