10 Product Specifications
10-2. Detection principle
RP-D58 Series
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10-2. Detection principle
[Flow Sensor]
The flow sensor has a circuit that can output a contact signal when the flow rate drops below the preset
level.
The flow sensor is a hot-wire type with a Wheatstone bridge consisting of a detecting element,
compensating element, and fixed resistance. Contained in a flame arrester container allows it to be
flame-proof.
When the drawn air or gas comes into contact with the heated detecting element, the detecting element
temperature changes due to the heat dissipation, and the electrical resistance of the element changes
according to the temperature changes. Since the resistance changes are in proportion to the gas flow rates,
the Wheatstone bridge circuit can identify the changes as the flow rate.
Structure Diagram
D: Detecting element
C: Compensating
element
Fixed
resistance
Fixed
resistance
Variable resistor for bridge
equilibrium adjustment
Variable resistor for bridge
voltage adjustment
Switch
Power supply
Basic Circuit
VR
SW
E
Flow Sensor Appearance
