Thermal conductivity type flow switch Description:

A diagram of the current design is based on the principle of heat exchange (heat transfer / heat loss process), the probe module and built-in heating thermal module (mainly two thermistors, but not a standard RTD). When energized, the heating module converts electrical energy into heat. Shows the flow of heat conduction is closely related to the measured fluid flow rate, if there is no medium flow pipe, heating module receives heat thermal module is a fixed value, and when the fluid medium flows through the current probe shown, thermal module the received heat medium flow rate variation with the change, so that the offset value is changed between the two thermistor. This deviation signal microelectronic circuit elements into electrical signals, the processor then converts it into 4-20mA current signal or the set flow rate corresponding to the contact signal output.
Current trend shows the thermal conductivity probe and traffic signal processor integrated integration, six LED indicators provide a status display liquidity, the switching operation can be simple protection potential value screws under the front panel to adjust, and multiple output transistor form, relay and analog etc. facilitate your choice.

typical application

Mainly used in the compressor and circulating water systems, air conditioning systems, refrigeration systems, filling systems to monitor traffic flow pump start and stop the system, lubrication and cooling system monitoring, food processing, mixing processing.
Hydropower stations, water plants, sewage treatment plants, paper mills and other water supply system and the size of the flow interruption monitoring; deep well water pumping air line protection; unit size and lubricating oil flow interruption system monitoring, thermal oil circulating oil system flow size and interrupt monitoring.

Technical Parameters

Measuring range: Water 0 - 5m / s
Oil 0 - 10m / s
Gas 0 - 100 m / s
Operating voltage: DC24V / AC220V
Operating temperature range: -25 ℃ - 80 ℃
Temperature reaction time: ≤12s
Maximum pressure: 100bar
Switching time: ON: Typical 2s (1-13s)
OFF: Typical 2s (1-15s)
Temperature gradient:. Max 250k / min
Current consumption: ≤65mA
Switching current: ≤400mA
Probe material: SUS 316L
Interface: G1 / 2 "(Special Order)
Protection: IP67
output method:
P: three-wire DC PNP output (with short circuit and reverse electrode
protection)
N: three-wire DC NPN output (with short circuit and reverse electrode
protection)
R: relay output (contact capacity: AC220V / 1A,
DC30V / 0.4A)
C: 4-20mA output
LEDs: 6 LED indicates the output status
Red light flow rates below the operating point
(Non-conducting transistor / relay does not operate)
Yellow light indicates flow rate equal to or higher than the operating point
(Transistor is turned on / relay)
A green light indicates the degree of flow rate higher than the operating point

Notable features

Easy installation
Simple adjustment
Wide range of applications
Almost no pressure loss
Great For diameter range
Adjustable set point
Pressure up to 100bar
Direct indicator shows traffic trends
Processor design with one probe
Optional relays, transistors, analog output
The probe uses a special anti-fouling paint, stain stronger

Probe housing material

HarHn flow monitor housing material Teflon and stainless steel and other materials, the user selects, not only to consider the case of the measured medium, but also pay attention to the use of the environment: whether in a hazardous area, the availability of high temperature, high pressure the requirements.
As a material made of Teflon to flow monitor suitable for monitoring corrosive media flow state; but because of its low thermal conductivity, and the stainless steel flow monitor compared to a longer response time.

On / Off Time

Start time refers to the specific conditions, traffic monitoring generates the time required for the output signal. In contrast with the opening time and closing time is when charging speed is reduced, the time traffic monitoring to detect the output signal.
Flow Monitor stainless steel typical on / off time of 2s.