Honeywell STD730 Differential Pressure Transmitter Unit

Module Feature

STD730-E1HC4AS-1-A-AHB-11S-A-1 belongs to Honeywell SmartLine STD700 series differential pressure transmitter. It adopts capacitive sensing element with static pressure and temperature automatic compensation, high measurement stability and wide turndown ratio. Supports external zero and span adjustment via local push buttons and LCD display. Built-in comprehensive diagnostic functions, dual seal design meets ISA 12.27.0 safety standard, SIL2 certification available. Two-wire loop-powered design, 4-20mA analog signal superimposed with HART7 digital protocol. Widely applied for orifice flow measurement, tank level measurement, filter differential pressure monitoring in petrochemical, power plant and oil & gas facilities.

Working principle

High side and low side process pressure act on the isolation diaphragm of the sensor module. The differential pressure causes capacitance change of the sensing cell. The internal circuit converts capacitance variation into standard 4-20mA signal, and embeds digital HART communication data. The transmitter continuously compensates measurement deviation caused by static pressure and ambient temperature, uploads process value, sensor status and diagnostic information to DCS system.

Onboard components

Capacitive sensor assembly, stainless steel isolation diaphragm, signal conditioning PCB, HART communication chip, LCD local display, push button adjustment unit, pressure manifold connection base, flameproof housing.

LED indicators

No separate LED; measurement and fault status are displayed on LCD screen.

Hardware self-diagnosis

Sensor drift detection, overpressure alarm, temperature abnormality check, loop current fault diagnosis, memory integrity self-test, records diagnostic codes accessible via HART host.

Programming software

Honeywell Field Device Manager, HART communicator, used for range setup, unit configuration, trim calibration and fault diagnosis.

Electrical & Process Parameters

Model:STD730-E1HC4AS-1-A-AHB-11S-A-1 Brand:Honeywell Device type:Differential Pressure Transmitter Power supply:10.5~42VDC loop powered Signal output:4-20mA + HART 7 Protocol Accuracy:0.065% FS Max span:100 psi (7 bar) Safety:SIL2 capable Protection:IP66/IP67, explosion-proof option

Mechanical & Structure

Mounting:2 inch pipe mount or manifold mount Protection class:IP66 / IP67 Housing:Cast aluminum transmitter head, 316L stainless steel wetted parts

Environmental

Operating temperature:-40℃ ~ +85℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non-condensing Certification:CE, UL, FM, SIL2 compliant Status: Honeywell original SmartLine differential pressure transmitter

Installation

Isolate process pressure before installation. Mount Honeywell STD730 transmitter on 2-inch pipe bracket or three-valve manifold. Connect high/low pressure impulse piping, wire two-wire signal cable to control system. Perform zero trim after piping pressurization, verify range and HART communication.

Interface

High pressure port, low pressure port, 1/2"NPT electrical entry, HART communication interface.

Diagnostic

Current fixed at 4mA: sensor damage or impulse line blockage. Current locked at 20mA: overpressure condition. HART communication no response: loop polarity reversed or loop resistance insufficient.

Product Brief

Honeywell STD730-E1HC4AS-1-A-AHB-11S-A-1 SmartLine STD700 differential pressure transmitter, HART7, SIL2 capable, for flow, level and differential pressure monitoring in industrial process control.