HM SERIES — GERMAN OEM PRESSURE SENSOR
HM12-UC7 German OEM Pressure Sensor
The HM12-UC7 is an advanced dry ceramic capacitive pressure sensor with built-in digital UART/SPI interface, co-developed with German HELM. Featuring 24-bit pressure measurement resolution and optional 16-bit temperature sensing, it delivers ±0.075% FS accuracy with 200× overload protection. Its 99.99% alumina ceramic diaphragm operates from −0.1 to 7 MPa across −40 to 125°C — purpose-built for smart transmitter designs, IoT systems, and Industry 4.0 applications.

Overview | Specifications | Features | Applications | Ordering Guide | FAQ
Product Overview
The HM12-UC7 is a digital-output dry ceramic capacitive pressure sensor manufactured by German HELM using 99.99% high-purity alumina ceramic. Unlike the analog UC1 variant, the UC7 features an integrated ASIC with UART and SPI digital interfaces, 24-bit pressure measurement resolution, and optional 16-bit temperature compensation — making it the most advanced sensor in the HELM OEM lineup. The UC7 variant features a digital UART/SPI interface with 24-bit pressure measurement and optional 16-bit temperature sensing, ideal for smart transmitter and IoT applications.
Unlike conventional diffused silicon or metal-foil sensors that require oil-fill isolation, the HM12-UC7 employs a dry ceramic diaphragm that directly contacts the process media. This eliminates the risk of fill-fluid leakage and contamination — a critical advantage in food, pharmaceutical, and medical applications where media purity is essential. The ceramic material is inherently corrosion-resistant, wear-resistant, and immune to shock and vibration damage.
With measurement ranges from as low as 0.5 kPa (micro-pressure) up to 7 MPa, and overload protection reaching 200× full scale on low ranges, the HM12-UC7 solves the traditional weakness of micro-pressure sensors — poor overload tolerance. The standardized 4500 mV high-level output provides excellent signal-to-noise ratio and interference immunity, making it the preferred OEM sensing element for manufacturers including E+H, ABB, Honeywell, Emerson, and VEGA in their industrial pressure transmitter product lines.
Technical Specifications
| Parameter | Specification |
|---|---|
| Measuring Range | −0.1 to 7 MPa (gauge); 0 to 7 MPa (absolute); ±2.5 kPa to ±100 kPa (compound) |
| Pressure Type | Gauge, Absolute, Compound (positive/negative) |
| Overload Capacity | 10× to 200× FS (higher ratio at lower ranges) |
| Overall Accuracy | ±0.075% FS (best); Typical: ±0.1% FS; Max: ±0.2% FS |
| Long-Term Stability | Typical: ±0.05% FS/year |
| Zero Temperature Drift | Typical: ±0.005% FS/°C; Max: ±0.01% FS/°C |
| Sensitivity Temperature Drift | Typical: ±0.005% FS/°C; Max: ±0.01% FS/°C |
| Operating Temperature | −40 to 125°C |
| Compensated Range | −20 to 80°C |
| Power Supply | 5 VDC |
| Supply Current | < 2 mA |
| Zero Output | 500 ± 100 mV |
| Full-Scale Output | 4500 ± 100 mV |
| Insulation Resistance | > 2 kV |
| Diaphragm Material | 99.99% high-purity alumina ceramic |
| Compatible Media | Gases and liquids compatible with ceramic |
| Range Turndown | 10:1 |
| Output Type | Analog millivolt + Digital UART/SPI (ratiometric to supply) |
| Digital Resolution | 24-bit (pressure) / 16-bit (temperature, optional) |
| Measurement Cycle | 1.25 ~ 80 ms (configurable) |
| Power Consumption | 2.5 ~ 10 mW |
Key Features
Dry Ceramic Capacitive Technology
No oil fill or isolation diaphragm required. The dry ceramic sensing element directly contacts the process media, eliminating contamination risk and making it inherently suitable for food-grade and pharmaceutical applications.
Exceptional Overload Protection
Overload capacity ranges from 10× to 200× full scale depending on range selection. At low pressure ranges, the ceramic diaphragm safely bottoms out against the substrate without damage — solving the traditional micro-pressure overload problem.
German HELM Precision Engineering
Manufactured by HELM in Germany using 99.99% high-purity alumina ceramic with laser-trimmed signal conditioning. Each sensor undergoes factory calibration with internal temperature compensation for reliable performance across the full operating range.
Digital UART/SPI Interface
Standardized 4500 mV full-scale output provides excellent signal-to-noise ratio and strong interference immunity. The ratiometric output to the 5 VDC supply simplifies integration with most industrial ADCs and signal conditioning circuits.
Wide Temperature Range
Operates from −40 to 125°C with compensated accuracy across −20 to 80°C. Metal-sputtered sensor base enhances EMC performance and reduces mounting sensitivity for consistent measurement in harsh industrial environments.
Versatile Pressure Range Coverage
Available from micro-pressure (0.5 kPa) to high pressure (7 MPa) in gauge, absolute, and compound configurations. The 10:1 range turndown capability allows a single sensor model to cover multiple application requirements.
Applications
Industrial Pressure Transmitters
Core OEM sensing element for manufacturing industrial-grade pressure transmitters. The high-level millivolt output and EMC-enhanced base integrate directly with standard signal conditioning circuits used by major transmitter manufacturers worldwide.
Food & Beverage Processing
Dry ceramic construction eliminates contamination risk from fill fluids. The flush, flat diaphragm surface resists buildup and is easy to clean, meeting hygiene requirements for process pressure monitoring in food and beverage production lines.
Pharmaceutical & Medical
No intermediate fill liquid means zero risk of product contamination. The ceramic sensor’s chemical inertness and wide sterilization temperature tolerance make it ideal for pressure monitoring in pharmaceutical reactors, autoclaves, and medical gas systems.
HVAC & Building Automation
Micro-pressure capability down to 0.5 kPa with compound pressure options (±2.5 kPa, ±10 kPa) enables precise differential and static pressure measurement in air handling units, cleanroom pressurization, and duct pressure monitoring.
Water & Wastewater Treatment
Corrosion-resistant ceramic diaphragm withstands aggressive media and particulate-laden fluids without degradation. The 200× overload protection handles water hammer events that would damage conventional silicon-based sensors.
Laboratory & Calibration
±0.075% FS accuracy with excellent long-term stability (±0.05% FS/year) and low temperature drift provides reliable reference-grade performance for laboratory pressure measurement and calibration bench applications.
Ordering Guide
| Selection | Options |
|---|---|
| Pressure Range | Select from: 0–2.5 kPa, 0–10 kPa, 0–20 kPa, 0–40 kPa, 0–100 kPa, 0–200 kPa, 0–400 kPa, 0–1 MPa, 0–2 MPa, 0–4 MPa, 0–7 MPa; Compound: ±2.5 kPa, ±10 kPa, ±100 kPa |
| Pressure Type | G: Gauge; A: Absolute |
| Sensor Variant | UC1: Analog millivolt output (standard) |
| Accuracy Grade | A: ±0.075% FS; B: ±0.1% FS; C: ±0.2% FS |
| Temperature Compensation | Standard: −20 to 80°C |
| Process Connection | Standard ceramic sensor element (consult factory for mounting options) |
| Custom Options | Contact sales for custom ranges, special calibration, or volume pricing |
For custom configurations, special calibration requirements, or volume pricing, contact our technical sales team with your application details and we will provide a tailored HM12-UC7 configuration proposal.


