DIFFERENTIAL PRESSURE MEASUREMENT

Differential Pressure Transmitters

Industrial DP transmitters for flow measurement, filter monitoring, and level detection in sealed tanks. 4-20mA, HART, and RS485 outputs with accuracy up to ±0.075% FS. Ranges from 0~1 kPa to 0~10 MPa.

📘 New to DP measurement? Learn how differential pressure transmitters work — a 2026 engineer’s guide covering sensor technologies, 4-20 mA wiring and manifold commissioning.

Our Differential Pressure Transmitter Range

From compact micro-DP sensors for HVAC air flow to smart capacitive DP transmitters for process plants — select the model that matches your application requirements.

HM30 Micro Differential Pressure Transmitter

HM30

Compact DP transmitter for micro pressure differences from 0~1 kPa. Ideal for HVAC air flow, clean room pressure monitoring.

Range: 0~1 kPa to 0~10 kPa

Accuracy: ±0.5% FS

Output: 4-20mA / 0-5V

HM31 Differential Pressure Transmitter

HM31

Mid-range differential pressure transmitter for industrial flow and filter monitoring applications.

Range: 0~6 kPa to 0~3.5 MPa

Accuracy: ±0.5% FS

Output: 4-20mA / 0-5V

HM3051 Smart DP Transmitter

HM3051

HART-protocol smart differential pressure transmitter with capacitive sensing cell for process control.

Range: 0~1 kPa to 0~10 MPa

Accuracy: ±0.075% FS

Protocol: HART

HM1151 Capacitive DP Transmitter

HM1151

Traditional capacitive differential pressure transmitter compatible with 1151/3051 industry standards.

Range: 0~1 kPa to 0~10 MPa

Accuracy: ±0.1% FS

Output: 4-20mA

How to Choose the Right DP Transmitter

Step 1 — Determine your pressure range: For HVAC and clean room (0~1 kPa), choose the HM30. For orifice plate flow measurement and filter monitoring (6 kPa~3.5 MPa), choose the HM31. For process plant applications requiring HART communication (up to 10 MPa), the HM3051 or HM1151 are recommended.

Step 2 — Choose your output signal: Standard 4-20mA (2-wire) is the most common for industrial control loops. Voltage output (0-5V, 0-10V) is preferred for direct data acquisition. RS485/Modbus is used for digital communication networks. HART protocol (HM3051) enables remote configuration and diagnostics over the same 4-20mA wiring.

Step 3 — Consider wetted materials and process conditions: Standard 316L stainless steel diaphragms suit most industrial fluids. For highly corrosive media (strong acids, chlorine), consult our engineers for Hastelloy C or tantalum options. Operating temperature, static pressure rating, and process connection type (flanged, threaded, or remote seal) should also match your installation requirements.

Frequently Asked Questions

A differential pressure transmitter measures the pressure difference between two ports (high and low side). A gauge pressure transmitter measures pressure at one port relative to atmosphere. DP transmitters are essential for flow measurement with orifice plates, filter monitoring, and level measurement in sealed tanks.

Install an orifice plate or Venturi tube in the pipeline. Connect the upstream (high) and downstream (low) pressure taps to the DP transmitter. The DP transmitter outputs a signal proportional to the square of flow velocity. Use a flow computer or DCS/PLC with square root extraction to convert DP to flow rate.

For general industrial monitoring, ±0.5% FS (HM30/HM31) is sufficient. For custody transfer, fiscal metering, or critical process control, choose ±0.075% FS (HM3051). The HM1151 at ±0.1% FS is suitable for most process plant applications where HART is not required.

Need Help Selecting a DP Transmitter?

Tell us about your application — pipe size, media type, flow range, or the pressure drop you need to measure. Our engineers typically respond within 12 business hours with a customized recommendation.

Our engineers typically respond within 12 business hours with detailed technical specifications and pricing.