MEASUREMENT SYSTEMS
BARTON
®
Cameron's Barton Differential Pressure Switches - 25235 Differential Pressure Switches
Models 289A and 291B
Barton
® DP switches are available in a wide variety of safeworking pressures and differential pressure ranges. Widely usedin applications that require measurement of differential pressure,flowrate, and liquid level, they provide accuracy, narrowdeadband, and repeatability of switch action at set point.
Features
•SWP to 6,000 PSI (414 bar)•Barton
® DPU Sensor/Actuator•NEMA-4/IP65 and Explosionproof Cases
•Wide Selection of DP Ranges (including absolute, zero-center, and split ranges)•Pulsation Dampening (selected models)
Actuating Units
•The
indicator is actuated by a rupture-proof bellows differential pressure unit (DPU) with integral temperature compensation.•The M199 DPU features dual, liquid-filled, bellows designed to withstand repeated overranges equal to the safe working pressure of the housings without a change in calibration.
Switch Contacts
•Barton
® switches are available in configurations with 1 to 4 adjustable snap-action type SPDT switches, with DPDT and hermetically-sealed switches available as specials on selected models. Switches can be set for high or low, or both high and low on units with two or more contacts.•Chosen for their reliability under severe shock andvibration conditions, the contacts are adjustable from
5 to 95% of full scale range, and are set with a control screw located flush with the scaleplate. Contacts can be set to open or close (by reversing wires at terminal) with increasing or decreasing differential pressure – providing maximum flexibility.
Indicating Mechanism
•The indicating pointer traverses a 270 degree arc, providingexcellent readability. It is driven by a precision-jeweled rotary movement that multiplies rotation of the torque tube
through a gear and pinion to the pointer. The movement employs a thermally stable Ni-Span-C hair spring.•The movement has a micrometer screw for convenient range adjustments. Zero/range adjustments can be made without removing the scale plate or pointer. Linearity adjustments are readily accessible after removal of the scale plate.
