Diffused Silicon Pressure Transmitter with Digital Display for Precision Measurement

Some applications need more than a raw pressure signal: they need a sensor with the stability of silicon, the accuracy of a laboratory instrument, and a local display that tells the operator the value at a glance. The QWY-30 diffused silicon pressure transmitter delivers exactly that, with 0.075% accuracy, an 8 ms response and ranges down to 0-1 mH2O.

Why Do You Need a Diffused Silicon Pressure Transmitter?

Measurement requirements are getting stricter: energy efficiency programs demand accurate low-range pressure and level data, fast machines need pressure signals that keep up with rapid cycles, and operators want to read values directly at the instrument without a separate display. Traditional metal-foil strain gauge sensors drift with temperature and fatigue over time, while high-end transmitters are often too expensive for everyday applications. Diffused silicon technology answers this need: it offers excellent accuracy, repeatability and long-term stability at a practical cost, because the sensing element is manufactured with semiconductor precision. When the application requires trustworthy low-range measurement, fast response and a clear local readout, the QWY-30 is the professional choice.

Working Principle: Piezoresistive Sensing on a Silicon Chip

The QWY-30 uses an imported diffused silicon sensing element. Piezoresistive resistors are diffused directly into a silicon wafer to form a Wheatstone bridge; when pressure deforms the silicon diaphragm, the resistors change value in proportion to the applied pressure, producing an electrical signal that is amplified and linearized by the transmitter electronics. This semiconductor construction gives the sensor high sensitivity, excellent repeatability and low hysteresis. The conditioned signal drives both the local digital display and a standard 4-20 mA output, with an accuracy of 0.075% and a response time of 8 milliseconds. A 316L stainless steel diaphragm isolates the silicon element from the process medium, while the housing provides IP67 protection.

Structural Advantages of the QWY-30

• Imported diffused silicon sensor: semiconductor-grade precision and stability.
• 0.075% accuracy: laboratory-class measurement for industrial use.
• 8 ms fast response: tracks rapid pressure changes in real time.
• Integrated digital display: local reading without extra instruments.
• Low ranges from 0-1 mH2O: measures tiny pressures other transmitters cannot resolve.
• 316L stainless steel diaphragm: corrosion-resistant process isolation.
• IP67 protection: dust-tight and water-resistant housing.
• 150%FS proof pressure: robust against overpressure events.

Pain Point Analysis: 4 Challenging Working Conditions

Application Cases

Product Advantages

• Imported diffused silicon sensing element
• 0.075% accuracy for precise measurement
• 8 ms response time for dynamic processes
• Integrated digital display for local reading
• Low ranges from 0-1 mH2O to 0-1500 mH2O
• 316L stainless steel diaphragm isolation
• IP67 dust-tight and water-resistant housing
• 150%FS proof pressure protection
• Gauge, absolute and sealed gauge pressure types
• Standard 4-20 mA output, OEM/ODM support

Technical Parameters

SEO FAQ

Q1: What is a diffused silicon pressure transmitter?

A diffused silicon pressure transmitter uses a sensing element made by diffusing piezoresistive resistors directly into a silicon wafer. When pressure is applied, the silicon diaphragm deforms and the resistors change their electrical resistance in proportion to the pressure, generating a signal that is conditioned into a standard output such as 4-20 mA. This semiconductor manufacturing approach produces sensors with high sensitivity, excellent repeatability, low hysteresis and good long-term stability, at a cost that makes them practical for everyday industrial use. The QWY-30 combines this proven technology with a digital display and rugged construction, delivering precision measurement for a wide range of liquid and gas applications.

Q2: What accuracy can I expect from the QWY-30?

The QWY-30 offers an accuracy of 0.075%, which is exceptional for an industrial pressure transmitter. This means the measured value deviates from the true pressure by no more than 0.075% of the calibrated span, across the full operating range and under reference conditions. This level of accuracy is achieved through the inherent precision of the diffused silicon element, combined with careful factory calibration and temperature compensation. For applications such as low-pressure measurement, tank level gauging and energy monitoring, where small errors translate into significant cost or quality impacts, the 0.075% accuracy of the QWY-30 provides the confidence that ordinary transmitters cannot match.

Q3: What measuring ranges are available?

The QWY-30 is available with measuring ranges from 0-1 mH2O up to 0-1500 mH2O, which corresponds to very low pressures through moderate pressures suitable for water, air and light chemical service. The low-range capability down to 1 mH2O (approximately 10 mbar) makes the transmitter suitable for applications such as duct static pressure, cleanroom differential pressure and shallow tank level measurement, where most industrial transmitters cannot provide a stable signal. The transmitter is factory-calibrated to the exact range ordered, and the 4-20 mA output is mapped across that span. If your application needs a pressure outside this range, our range includes other models to cover it.

Q4: Why is the 8 ms response time important?

Response time is the delay between a pressure change at the process and the corresponding change in the transmitter output. An 8 ms response means the QWY-30 reacts almost instantly, making it suitable for dynamic applications such as pump protection, compressor monitoring, hydraulic systems and fast-cycling machinery. In these applications, a slow transmitter can miss pressure spikes entirely or deliver outdated data to the control loop, leading to equipment damage or unstable control. The fast response of the QWY-30 ensures that protection relays receive the pressure information in time to act, and that control loops can respond quickly to disturbances, improving both safety and process performance.

Q5: What does the digital display show and how is it used?

The integrated digital display shows the current pressure value in the configured engineering units, such as mH2O, bar, psi or kPa, allowing operators to read the pressure directly at the instrument without a separate display or handheld communicator. This is valuable during commissioning, when verifying the process against the control system reading, and during routine walk-through checks. The display also simplifies troubleshooting, because an operator can immediately see whether the problem is in the process or in the signal chain. If the control room value differs from the display, the issue is in the wiring or the control system input rather than the sensor.

Q6: Can the transmitter handle overpressure events?

Yes. The QWY-30 is rated for a proof pressure of 150%FS, meaning it can withstand pressures up to 1.5 times its full-scale rating without permanent damage or calibration shift. Overpressure events are common in real plants: a blocked line, a pump starting against a closed valve, or a surge in the process can momentarily push the pressure well above the normal operating range. The 150%FS proof rating absorbs these transients, and the transmitter returns to normal operation once the pressure returns to the calibrated range. For applications with frequent severe overpressure, we recommend discussing the duty with our engineers, who may suggest a higher-range model or additional protection.

Q7: What pressure types are available?

The QWY-30 supports gauge pressure, absolute pressure and sealed gauge pressure measurement. Gauge pressure measures pressure relative to the local atmosphere and is the standard choice for most tanks, pipes and vessels. Absolute pressure measures relative to a perfect vacuum and is used in applications such as vapor pressure measurement, altitude compensation and some scientific processes. Sealed gauge pressure measures relative to a sealed reference at approximately atmospheric pressure, which is common in applications where the venting of a true gauge reference is impractical. You can select the pressure type that matches your application, and the transmitter is calibrated accordingly at the factory.

Q8: Is the transmitter suitable for outdoor or washdown environments?

Yes. The QWY-30 has an IP67 ingress protection rating, meaning it is completely protected against dust and withstands temporary immersion in water up to 1 meter for 30 minutes. This makes it suitable for outdoor installations, pump rooms, washdown areas in food plants and other wet environments where moisture would damage less-protected instruments. The 316L stainless steel diaphragm and corrosion-resistant construction further support service in humid and mildly corrosive atmospheres. For installations exposed to continuous high-pressure washdown or aggressive chemicals, please confirm the environmental requirements with our engineers so the correct sealing and material configuration is supplied.

Q9: How do I install and commission the transmitter?

Install the QWY-30 at the pressure tap using the appropriate process connection, such as NPT1/4 or the NPT3/8 adapter, with an isolation valve where the process must remain online during maintenance. Mount the transmitter so the diaphragm is not exposed to sediment buildup, and in gas service mount with the port below the body to allow condensate drainage. Wire the 4-20 mA loop to the correct terminals with proper polarity, observing the supply voltage requirements. During commissioning, verify the display and the control system reading against a reference gauge, check the zero point with the process isolated and vented, and confirm the range configuration. The user manual provides the complete procedure.

Q10: What customization and support do you provide?

As the manufacturer, we offer comprehensive customization for the QWY-30, including measuring range, pressure type, output configuration, process connections, cable length and labeling, as well as OEM and ODM programs for equipment manufacturers. Every unit is factory-calibrated and tested before shipment, and calibration certificates are available on request. Our technical team provides application advice, installation support and troubleshooting assistance. Standard delivery is 5-8 working days with a monthly supply capacity of 100 pieces. Contact us with your pressure range, media and connection requirements, and we will provide a tailored recommendation and quotation.

Why Choose Our Diffused Silicon Pressure Transmitter?

The QWY-30 brings together everything engineers ask for in a modern pressure transmitter: the precision and stability of an imported diffused silicon sensor, 0.075% accuracy, an 8 ms response, low-range capability down to 1 mH2O, and a built-in digital display, all in an IP67 housing at a factory-direct price. As the manufacturer, we calibrate every unit to your exact range and stand behind it with responsive support and OEM flexibility. When your measurement needs precision and your operators need visibility, choose the QWY-30.