Thermal conductivity flow switch (explosion-proof type) NK33EX-150 model

Principle structure

The NK33EX-150 series thermal conductivity flow switch is based on the thermal principle and contains two resistors inside a closed probe, one of which is heated as the detection resistor and the other is not heated as the reference resistor; When the medium flows, the heat on the heating resistor is carried away, the resistance value is changed, and the difference between the two resistances is used as the basis for judging the flow rate.

The probe adopts an anti scaling coating, which can effectively prevent the adhesion of scale, rust and other dirt in the pipeline, with stronger anti fouling ability and more stable operation.

Product Features

The conical probe design can effectively prevent entanglement of objects in the medium. Fully waterproof shell design, waterproof adjustment knob, can be adjusted freely without dismantling the sealing screw, convenient and more reliable. Suitable for a wide range of pipe diameters, adjustable set points, optional anti-corrosion type, pressure resistance up to 100Bar, direct display of flow rate indicator light, optional relay, analog output or analog switch integrated output. Real time monitoring of liquid flow in pipelines is possible, with no moving parts, maintenance free, and easy installation. One model is used for various pipe diameters

Please provide switch output and 4-20mA analog output options, and use digital display of fluid flow rate percentage to achieve the following monitoring functions: medium flow, reducing/increasing flow rate; Existence/non existence of medium; Medium flow/static; Monitor the fluid flow velocity inside the pipeline, monitor flow interruption, or prevent pump idling.

Product Application

Widely used in industries such as petrochemicals, electricity, metallurgy, steel mills, papermaking, food processing, water treatment, battery factories, etc. Gas liquid dual-use type, can be used for pneumatic and hydraulic systems, can be used for flow monitoring of circulating water, cutting fluid and lubricating oil, as well as pump idle protection.

Technical Specifications

• Setting range: 1-150cm/s (water) 3-300cm/s (oil)
• 20-2000cm/s (air)
• Signal output: PNP, NPN, relay
• 1) Normally open+normally closed (SPDT)
• Power supply: 24V ± 20% DC2
• Power on: Maximum 400mA (PNP or NPN type)
• Maximum 3A 24VAC/DC (relay type)
• No load current: maximum 80mA
• Traffic indication: digital display
• Setting method: button setting
• Pressure resistance range: 100bar (maximum customizable 40MPa)
• Medium temperature change: ≤ 4 ℃/s
• Response time: 1-13s, typical value of 2s
• Initialization time: approximately 8 seconds
• Electrical protection: reverse phase, short circuit, overload protection
• Explosion proof grade: ExdII CT6
• Protection level: IP67
• Medium temperature: -20 ° C to 100 ° C (customizable to -60 ° C to 150 ° C)
• Environmental temperature: -20 ° C to 80 ° C
• Storage temperature: -20 ° C to 100 ° C
• Wiring method: Terminal wiring M20 * 1.5
• Material: Probe: Stainless steel (customizable 316L/titanium alloy/polytetrafluoroethylene material)
• Shell: Cast aluminum
• Repetition accuracy: ± 2%

Wiring Diagram

Size Chart

Button Setting Instructions