D-315-230 Differential Pressure Transmitter Unit

Module Feature

D-315-230 is a diaphragm-type differential pressure transmitter.

The built-in sensing diaphragm detects the pressure difference between high-pressure and low-pressure tapping ports. Internal signal conditioning circuit converts tiny diaphragm displacement into standard 4-20mA analog signal. This variant supports 230V AC power supply, zero and span adjustable on site. Compact enclosure, resistant to dust and moderate moisture. It is commonly used for air filter blockage alarm, fan static pressure monitoring, air duct differential supervision. Widely stocked as maintenance spare for HVAC, clean room and light process skid control cabinet.

Working principle

Pressure difference acts on two sides of the sensing diaphragm.

Diaphragm deformation changes the resistance/capacitance of sensing element. Electronics module amplifies, filters and converts the signal into linear 4-20mA output. 4mA corresponds to zero differential pressure, 20mA corresponds to full-scale differential value. The two-wire or three-wire signal is sent to PLC or DCS for indication and interlock alarm.

Onboard components

Sensing diaphragm, signal conditioning PCB, zero/span adjustment potentiometer, high/low pressure process port, wiring terminal block, sealing assembly and die-cast aluminum housing.

LED indicators

Power and fault LED are integrated on the electronics cover.

Hardware self‑diagnosis

Internal circuit monitors supply voltage and loop integrity. Calibration is performed by differential pressure calibrator.Programming softwareNot applicable, analog transmitter, local adjustment only.

Electrical & Process Parameters

Model:D-315-230 Brand:OEM industrial instrument Device type:Diaphragm differential pressure transmitter Function:Continuous differential pressure measurement and analog signal output for air system and filter monitoring

Mechanical & Structure

Mounting:Wall or pipe bracket mounting Protection class:IP65 Housing:Die-cast aluminum sealed enclosure

Environmental

Operating temperature:-20℃ ~ +70℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE Status:Original industrial instrument spare

Installation

Isolate power supply before replacement.

Connect high side and low side pressure port correctly, route signal cable, perform zero calibration, test full span output and alarm trigger after commissioning.

Interface

High pressure tap, low pressure tap, power and 4-20mA signal terminals.

Diagnostic

Fixed at 4mA: Sensing diaphragm rupture, supply loss. Saturated at 20mA: Overrange differential pressure, internal electronics damage. Unstable reading: Piping condensation, pressure port blocked.

Product BriefD-315-230 transmitter, industrial differential pressure transmitter spare for HVAC filter and air duct monitoring replacement.