High-Resolution Resonant Pressure Transducer for Critical Control
1. Why You Need It
Custody transfer and critical process control demand the highest accuracy and long-term stability, because small errors translate directly into money or risk. This resonant silicon transducer delivers ±0.025% accuracy and less than 0.1% drift over ten years. Its frequency-based output eliminates the analog drift that plagues conventional sensors, making it the reference choice for fiscal metering and precision process loops where every measurement counts.
2. Working Principle
Pressure loads a silicon resonant element whose natural vibration frequency changes with applied stress. The sensor measures this frequency shift with extreme precision and converts it to a digital signal, then to 4-20 mA with HART, Foundation Fieldbus or PROFIBUS PA. Because frequency is an inherently stable, drift-free quantity — unlike analog voltage or resistance — the measurement remains accurate over many years without recalibration.
3. Key Advantages
- ±0.025% accuracy
- <0.1% drift over 10 years
- Frequency output, no analog drift
- HART / FF / PROFIBUS PA options
- Gauge / absolute / sealed gauge
- 316L diaphragm
- 9-32 V DC power
- CL150 (DN25) connection
- Suitable for custody transfer
- Long-term calibration stability
Common Pain Points & Solutions
| Problem | Conventional Issue | Our Solution | Result |
|---|
| Fiscal metering accuracy | Standard sensors drift | ±0.025% resonant accuracy | Meets custody transfer spec |
| Frequent recalibration cost | Sensors drift and need calibration | <0.1% drift / 10 years | Fewer calibrations, lower cost |
| Analog signal drift | Analog electronics degrade | Frequency-based output | Stable long-term signal |
| Multi-protocol plant | Single-protocol limits | HART / FF / PROFIBUS PA | Integrates with any DCS |
Application Cases
Industry: Oil & Gas
Application: Custody transfer metering
Medium: Crude oil / condensate
Pressure Range: 0-10 MPa
Operating Temperature: -20 to 80 °C
Installation Environment: Metering skid
Customer Challenge: Fiscal-grade accuracy
Previous Problem: Standard sensor drift errors
Solution: Resonant transducer, FF output
Installation Location: Metering station
Result: Fiscal-grade, compliant metering
Industry: Petrochemical
Application: Reactor pressure control
Medium: Process hydrocarbon
Pressure Range: 0-4.0 MPa
Operating Temperature: 10-150 °C
Installation Environment: Process area
Customer Challenge: Precise loop control
Previous Problem: Insufficient accuracy
Solution: Resonant transducer, HART
Installation Location: Reactor vessel
Result: Precise, stable control
Industry: Power
Application: Turbine inlet pressure
Medium: Steam / gas
Pressure Range: 0-6.0 MPa
Operating Temperature: 50-300 °C
Installation Environment: Power plant
Customer Challenge: Accurate efficiency data
Previous Problem: Drift distorted efficiency
Solution: Absolute resonant transducer, PA
Installation Location: Turbine inlet
Result: Accurate efficiency monitoring
Industry: Calibration Lab
Application: Reference pressure standard
Medium: Gas
Pressure Range: 0-1.0 MPa
Operating Temperature: 20-25 °C
Installation Environment: Metrology lab
Customer Challenge: Trusted reference standard
Previous Problem: Reference drifted
Solution: 10-yr stable resonant standard
Installation Location: Calibration bench
Result: Trusted, stable reference
Technical Specifications
| Specification | Value |
|---|
| Sensor Element | Silicon resonant |
| Accuracy | ±0.025% of span |
| Long-term Stability | <0.1% over 10 years |
| Output | 4-20 mA / 0.5-4.5 V / 0-5 V / 1-5 V |
| Protocol | HART / FF / PROFIBUS PA |
| Diaphragm Material | SS316 |
| Pressure Type | Gauge / Absolute / Sealed Gauge |
| Connection | CL150 (DN25) |
FAQ
Q: What is a resonant pressure transducer?
A resonant pressure transducer measures pressure by detecting the frequency change of a silicon resonant element under applied stress. Pressure loads the element, shifting its natural vibration frequency, which is measured with extreme precision. Because frequency is a digital, drift-free quantity, the transducer achieves accuracy and stability that analog sensors cannot match over long periods.
Q: How accurate is it?
The transducer delivers ±0.025% of span accuracy, which is among the highest available for industrial pressure measurement. This level of precision is required for custody transfer and critical process control, where measurement errors directly affect billing, yield or safety. It is also suitable as a reference standard in calibration laboratories.
Q: How stable is it over time?
Stability is better than 0.1% drift over 10 years. This exceptional long-term stability dramatically reduces the frequency of recalibration and lowers the total cost of ownership. In custody transfer applications, it means the meter remains compliant and accurate for a decade or more without intervention.
Q: What communication protocols are supported?
The transducer supports HART, Foundation Fieldbus (FF) and PROFIBUS PA. These digital protocols allow integration with a wide range of DCS and asset-management systems, and enable remote configuration and diagnostics. The multi-protocol availability lets the same instrument fit different plant automation standards.
Q: Why is frequency output better than analog?
Frequency is a digital, drift-free quantity. Unlike analog voltage or current, which degrade with temperature, age and component tolerances, a frequency measurement does not drift over time. This is the key reason resonant sensors maintain their accuracy for years, avoiding the calibration burden of analog devices.
Q: What is the diaphragm material?
The diaphragm is 316 stainless steel (SS316), providing good corrosion resistance for common process media such as oil, gas, water and many chemicals. For highly aggressive media, alternative diaphragm materials can be specified. The SS316 diaphragm is the standard for general industrial and custody transfer service.
Q: What pressure types are available?
The transducer offers gauge, absolute and sealed gauge pressure types. Gauge pressure is referenced to atmosphere, absolute to vacuum, and sealed gauge to a fixed internal reference. The correct type is selected based on the application — for example, absolute for barometric or vacuum-referenced measurement, gauge for general process use.
Q: Is it suitable for custody transfer?
Yes, the ±0.025% accuracy and 10-year stability make it suitable for custody transfer metering, where the measurement is used for fiscal billing between parties. The frequency-based sensing and digital output provide the accuracy, repeatability and traceability that fiscal metering regulations require.
Q: How does it compare to a strain-gauge transmitter?
A strain-gauge transmitter measures resistance change, which drifts with temperature and age and typically offers 0.1-0.25% accuracy. A resonant transducer measures frequency, which is inherently stable, delivering ±0.025% accuracy and <0.1% drift over 10 years. The resonant sensor costs more but is the right choice where accuracy and long-term stability justify the investment.
Q: Where is it used?
It is used in oil and gas custody transfer, petrochemical reactor control, power plant turbine monitoring and calibration laboratories. Anywhere that high accuracy, long-term stability and traceability are required, the resonant pressure transducer is the reference-grade instrument of choice.
