HM Series — Differential Pressure Transmitters
HM30 Micro Differential Pressure Transmitter
Precision micro differential pressure and wind pressure transmitter for HVAC, cleanroom, and industrial ventilation applications. Measures from 500 Pa to 700 kPa with ≤2 ms response time, ±0.1% FS accuracy option, and optional intrinsically safe (Ex ia) certification for hazardous environments.
Range: 500 Pa–700 kPa
Accuracy: ±0.1% FS
Response: ≤2 ms
Ex ia Certified
Product Overview
The HM30 Micro Differential Pressure Transmitter is a precision instrument designed for measuring low differential pressure and wind pressure in industrial and commercial environments. Built with German-engineered sensor components and a normalized circuit design with proprietary stress isolation technology, the HM30 converts differential pressure signals into industry-standard 4–20 mA or voltage output signals with exceptional accuracy and long-term stability.
The transmitter covers a wide measurement range from 500 Pa to 700 kPa in both positive differential and negative (vacuum) pressure configurations. Its normalized design ensures consistent quality across production batches, while the compact aluminum alloy or 304 stainless steel housing provides durable protection rated to IP65 or IP67. An optional intrinsically safe (Ex ia IIC T5) version is available for deployment in hazardous gas environments.
With a rapid response time of ≤2 ms and accuracy options down to ±0.1% FS, the HM30 is the preferred choice for HVAC duct pressure monitoring, cleanroom differential pressure control, furnace draft measurement, fan performance testing, and environmental air quality management systems. Field-adjustable zero and span simplify on-site calibration without specialized equipment.
Technical Specifications
| Parameter | Specification |
|---|---|
| Differential Pressure Range | 0–500 Pa to 0–700 kPa |
| Negative Pressure Range | 0 to -500 Pa … 0 to -100 kPa |
| Overload Capacity | 2× rated pressure |
| Measuring Medium | Non-corrosive, dust-free, dry gas |
| Accuracy (Combined) | ±0.4% FS (standard), ±0.25% FS (option 2), ±0.1% FS (option 3) |
| Long-Term Stability | Typical ±0.1% FS/year, Max ±0.2% FS/year |
| Response Time | ≤2 ms |
| Output Signals | 4-20 mA, 1-5 V, 0-5 V, 0.5-4.5 V |
| Supply Voltage | 12–36 VDC (typically 24 VDC) |
| Load Resistance | ≤(U-12)/0.02 Ω |
| Media Temperature | -20°C to +85°C |
| Compensation Range | -10°C to +55°C |
| Ambient Temperature | -10°C to +80°C |
| Zero Temp Drift | Typical 0.02% FS/°C, Max 0.05% FS/°C |
| Sensitivity Temp Drift | Typical 0.02% FS/°C, Max 0.05% FS/°C |
| Vibration Error | ≤±0.01% FS (X/Y/Z axis, 200 Hz/g) |
| Housing Material | Aluminum alloy (spray-coated) or 304 stainless steel |
| Process Connection | Φ8 barb with M10×1 mounting, M20×1.5, G1/4, custom |
| Electrical Connection | Cable (IP67, 2 m), DIN 43650 plug (IP65), Aviation connector (IP65) |
| Protection Rating | IP65 / IP67 |
| Explosion Protection | Ex ia IIC T5 (optional) |
| Insulation Resistance | >100 MΩ (500 VDC) |
| Weight | ~0.35 kg |
| Certifications | CE, Ex ia IIC T5 (optional) |
Key Features
Ultra-Fast 2 ms Response
Industry-leading response time of ≤2 ms enables real-time differential pressure monitoring for rapidly changing ventilation systems, fan testing, and dynamic process control applications.
Field-Adjustable Zero & Span
On-site calibration adjustment for both zero point and measurement span without requiring specialized tools, reducing installation time and enabling quick adaptation to changing process conditions.
Optional Intrinsic Safety
Available with Ex ia IIC T5 intrinsically safe certification for deployment in hazardous gas environments, enabling differential pressure monitoring in zones where explosive atmospheres may be present.
Lightning & RF Protection
Built-in surge suppression and radio frequency interference shielding protect the transmitter electronics in electrically noisy industrial environments near motors, VFDs, and power switchgear.
High Accuracy ±0.1% FS
Three accuracy tiers available — ±0.4% FS standard, ±0.25% FS enhanced, and ±0.1% FS precision — allowing cost-optimized selection based on application measurement requirements.
Compact & Versatile Housing
Lightweight 0.35 kg design in aluminum alloy or 304 stainless steel with IP65/IP67 protection. Multiple mounting and electrical connection options simplify integration into existing systems.
Applications
HVAC Duct Pressure Monitoring
Measure differential pressure across air handling units, filters, dampers, and ductwork to optimize airflow, detect filter clogging, and maintain building comfort and energy efficiency.
Cleanroom & Purification Systems
Maintain precise room-to-room and room-to-corridor pressure differentials in pharmaceutical, semiconductor, and hospital cleanrooms to prevent cross-contamination and ensure regulatory compliance.
Furnace Draft & Combustion Control
Monitor furnace pressure and negative draft to optimize combustion efficiency, prevent backdraft hazards, and ensure safe operation of industrial boilers, kilns, and heating systems.
Mine Ventilation Monitoring
Monitor underground mine ventilation airflow pressure to ensure adequate fresh air circulation, detect ventilation failures, and comply with mining safety regulations for worker protection.
Fan Testing & Wind Speed
Measure wind pressure and air velocity in fan test benches, wind tunnels, and industrial ventilation systems for performance validation, airflow balancing, and efficiency optimization.
Environmental & Emissions Control
Monitor stack pressure and flue gas flow in smoke treatment, dust collection, and environmental protection systems to ensure emission compliance and optimize scrubber/filter performance.
Ordering Guide
Use the model code structure below to specify your HM30 configuration. For custom requirements or assistance, contact our engineering team.
Model Code: HM30 (Range) – [Accuracy] – [Output] – [Connection] – [Electrical] – [Options]
| Position | Code | Description |
|---|---|---|
| Pressure Range | (0~500Pa) | Specify full-scale range (e.g., 0~1kPa, 0~10kPa, 0~100kPa) |
| Accuracy | 1 | ±0.4% FS (standard) |
| 2 | ±0.25% FS (enhanced) | |
| 3 | ±0.1% FS (precision) | |
| Output Signal | A1 | 4-20 mA (2-wire) |
| V1 | 1-5 V DC (3-wire) | |
| V2 | 0-5 V DC (3-wire) | |
| V3 | 0.5-4.5 V DC (3-wire) | |
| Process Connection | F1 | M20×1.5 thread |
| F2 | G1/4 thread | |
| F3 | Φ8 barb with M10×1 mounting screw | |
| F0 | Custom (specify) | |
| Electrical Connection | W1 | Cable outlet (IP67, 2 m) |
| W2 | DIN 43650 plug connector (IP65) | |
| W3 | Aviation connector (IP65) | |
| Options | E | Intrinsically safe Ex ia IIC T5 (requires safety barrier) |
Example: HM30 (0~500Pa) – 1 – A1 – F2 – W1 = 0–500 Pa range, ±0.4% FS accuracy, 4-20 mA output, G1/4 thread, cable outlet (IP67)
Related Products
Frequently Asked Questions
The HM30 measures differential pressure (the pressure difference between two points) and wind pressure. It supports both positive differential ranges (0–500 Pa to 0–700 kPa) and negative pressure ranges (0 to -500 Pa through 0 to -100 kPa). This makes it suitable for measuring duct pressure, room pressure differentials, furnace draft, and air velocity (via Pitot tube).
Yes. The HM30 is available with optional intrinsically safe (Ex ia IIC T5) certification. When ordered with the “E” option code, the transmitter is certified for use in Zone 0, 1, and 2 hazardous areas. Note that intrinsically safe installations require a certified safety barrier (Zener barrier or galvanic isolator) in the power supply circuit.
The HM30 is designed for non-corrosive, dust-free, dry gas media such as clean air, nitrogen, and inert gases. If your application involves dusty or humid gas, you should install an inline dust/moisture filter (drying filter) in the pressure tubing between the process and the transmitter to protect the sensing element, and replace it periodically.
The HM30 features built-in zero and span adjustment potentiometers accessible through the housing. To adjust zero, expose both pressure ports to atmospheric pressure (or equal pressure) and trim the zero pot until the output reads the correct zero value (e.g., 4 mA or 0 V). For span adjustment, apply a known reference pressure to the high port and trim the span pot. No specialized calibration equipment is required beyond a reference pressure source and a multimeter.
The HM30 is a complete transmitter with built-in signal conditioning, field-adjustable calibration, and optional explosion-proof certification — designed as a ready-to-install industrial instrument. The HE30 is a sensor-level product offering even lower pressure ranges (down to 100 Pa) with 0.5 Pa resolution, oil-free piezoresistive technology, and ultra-fast ≤4 ms response — designed for OEM integration and high-resolution laboratory applications. Choose the HM30 for general industrial HVAC and ventilation monitoring; choose the HE30 when you need the highest resolution at very low pressures or for sensor-level OEM integration.
Need a Differential Pressure Monitoring Solution?
Our engineering team can help you configure the HM30 for your specific HVAC, cleanroom, or ventilation monitoring application — including range selection, accuracy grade, housing material, and explosion-proof options. We also offer complete system solutions with multiple transmitters and data logging.
Our engineers typically respond within 12 business hours with detailed technical specifications and pricing.