High Sensitivity Micro Differential Pressure Transducer for Precise Low-Pressure Measurement

The most valuable signals in a plant are often the smallest ones: the pressure drop across a clogging filter, the tiny difference that reveals a leak, the subtle change that predicts a failure. The QWY-301 micro differential pressure transducer is built with high sensitivity to capture those small differences accurately and reliably.

Why Do You Need Micro Differential Pressure Measurement?

Many critical process conditions reveal themselves only as small pressure differences. A filter element slowly clogging shows up as a rising differential pressure long before flow degrades. An orifice plate measures flow through the tiny pressure drop it creates. A closed tank's level can be derived from the small difference between bottom and top pressure. A leak in a pressurized system appears as a subtle differential change. Measuring these small differences requires a transducer with high sensitivity and low noise, because an insensitive sensor buries the signal in its own error. The QWY-301 is designed exactly for this duty, detecting the small differentials that protect equipment, optimize processes and prevent failures.

Working Principle: Sensing the Difference Between Two Pressures

The QWY-301 measures the difference between two pressure inputs: the high-pressure port and the low-pressure port. The process pressures act on opposite sides of a sensing diaphragm, and the net deflection, proportional to the pressure difference, is converted by a high-sensitivity sensing element into an electrical signal. Because the element is optimized for small differentials, the transducer delivers excellent resolution and linearity superior to 0.25%FS across its range. The signal is conditioned for a 12-45 V DC supply, giving wide compatibility with industrial power systems, and the compact body with 1/4" NPT connections provides easy mounting in tight installations.

Structural Advantages of the QWY-301

• High sensitivity element: resolves small pressure differences other transducers miss.
• Linearity superior to 0.25%FS: dependable accuracy across the span.
• Wide pressure range -0.1 to 1600 bar options: one family covers micro to high pressure.
• Wide supply voltage 12-45 V DC: compatible with diverse power systems.
• Easy mounting design: compact body fits confined installations.
• 1/4" NPT process connections: standard, readily available fittings.
• M20×1.5 electrical connection: rugged industrial termination.
• 24-month warranty: long-term reliability backed by the manufacturer.

Pain Point Analysis: 4 Challenging Working Conditions

Application Cases

Product Advantages

• High sensitivity for micro differential measurement
• Linearity superior to 0.25%FS
• Pressure range options from -0.1 to 1600 bar
• Wide supply voltage 12-45 V DC
• Easy mounting compact design
• 1/4" NPT process connections
• M20×1.5 rugged electrical connection
• 24-month warranty
• OEM, ODM and OBM support
• Factory calibration and fast delivery

Technical Parameters

SEO FAQ

Q1: What is a micro differential pressure transducer?

A micro differential pressure transducer measures small differences in pressure between two points. It has two pressure ports, a high-pressure port and a low-pressure port, and its sensing element responds to the difference between them rather than to either absolute value. Micro differential refers to the transducer's ability to measure small pressure differences accurately, which requires high sensitivity and low noise. This makes it suitable for applications such as filter monitoring, low-velocity flow measurement, closed tank level and leak detection, where the meaningful signal is a small pressure difference that ordinary transducers cannot resolve reliably.

Q2: Why is high sensitivity important?

High sensitivity means the transducer produces a clear, usable output for small pressure changes. In micro differential applications, the pressure differences being measured can be very small, such as a few hundred pascals across a filter or a few millibar across an orifice. A transducer with low sensitivity or high noise will bury these small signals in its own error, making the measurement useless. The QWY-301's high-sensitivity element delivers strong, clean output for small differentials, so the control system sees real process changes rather than noise. This sensitivity is what enables early filter alarms, accurate low-flow measurement and reliable leak detection.

Q3: What is the difference between differential and gauge pressure measurement?

Gauge pressure measures the pressure of a process relative to the local atmosphere, using a single pressure port with a vented reference. Differential pressure measures the difference between two process pressures, using two ports, and is independent of atmospheric pressure. Differential measurement is used where the relationship between two points matters: across filters (clogging), across orifice plates (flow), between tank bottom and top (level in closed tanks), and across heat exchangers (fouling). The QWY-301 is a differential transducer, so it connects to both process points and outputs the difference, giving direct insight into the condition being monitored.

Q4: What pressure ranges are available?

The QWY-301 offers pressure range options from -0.1 bar through 0 to 1600 bar, covering both micro differential measurements and high-pressure applications. For micro differential duty, low-range versions measure small differences such as 0-100 mbar or 0-500 Pa with high sensitivity. For other duties, higher ranges up to 1600 bar are available, and the measurement range options extend to 0-1000 psi. The transducer is factory-calibrated to the exact range ordered, ensuring that the full output span represents your specific measurement span. Tell us your expected differential range and we will configure the appropriate version.

Q5: What power supply does the transducer need?

The QWY-301 accepts a wide supply voltage of 12 to 45 V DC, making it compatible with most industrial power systems, from 12 V battery supplies to 24 V plant loops and higher-voltage installations. The wide range means the transducer continues to measure accurately even when the supply voltage varies, which is common in plants with fluctuating loads or in battery-backed systems. This flexibility simplifies integration: the transducer can be connected to whatever supply is available at the installation point without a dedicated converter. The low power demand keeps the energy cost and heat generation minimal.

Q6: How is the transducer installed?

The QWY-301 features an easy-mounting compact design with 1/4" NPT process connections. For differential service, connect the high-pressure port to the upstream or higher-pressure point and the low-pressure port to the downstream or lower-pressure point, using impulse lines where the process points are separated. Ensure the impulse lines are free of blockages and, for gas service, install the transducer above the taps so condensate drains back; for liquid service, install below the taps so air bubbles rise back. The M20×1.5 electrical connection is terminated with a suitable cable gland, and the transducer body can be bracket-mounted in confined spaces thanks to its compact size.

Q7: What output does the transducer provide?

The QWY-301 provides a standard analog output proportional to the measured differential pressure, suitable for connection to PLCs, DCS systems, controllers and displays. The output is linear with the pressure difference across the calibrated range, so the receiving system converts it directly into engineering units such as mbar, Pa or psi. The signal conditioning is designed to preserve the high sensitivity of the sensing element, delivering a clean, stable output even for small differentials. If your application requires a specific output type or range mapping, please discuss it with our engineers when ordering.

Q8: Can the transducer measure high line pressures with small differentials?

Yes. A key capability of differential transducers is measuring a small difference while both ports are at a high common pressure, such as a 100 mbar drop across a filter in a 10 bar system. The sensing element responds to the difference while withstanding the static line pressure on both sides. When ordering for such duty, it is important to specify both the maximum line pressure and the differential range, so the correct version with appropriate overpressure rating is supplied. Our engineers will confirm the specifications match your operating conditions to ensure safe and accurate measurement.

Q9: What maintenance does the transducer require?

The QWY-301 requires minimal maintenance. Periodically check the impulse lines for blockage, leakage or condensation, as these are the most common sources of error in differential installations. Verify the zero point by equalizing both ports, which should produce a zero differential reading, and correct minor deviations with the zero adjustment. For dirty media, consider installing isolation valves and, where necessary, cleaning the impulse lines during maintenance. With its solid-state sensing element and 24-month warranty, the transducer provides long, reliable service with routine checks rather than frequent recalibration.

Q10: What support and customization do you offer?

As the manufacturer, we provide direct engineering support for the QWY-301, including range selection, installation planning and troubleshooting. We support OEM, ODM and OBM programs with custom ranges, custom outputs, connection options, labeling and packaging, and we can factory-calibrate the transducer to your exact differential span. Standard delivery is within 5-8 working days with a monthly supply capacity of 100 pieces. Contact us with your line pressure, differential range and application details, and we will recommend the correct configuration with a quotation.

Why Choose Our Micro Differential Pressure Transducer?

The QWY-301 is engineered for the measurements that matter most and are hardest to make: small pressure differences that reveal filter condition, flow rate, tank level and leaks. Its high sensitivity, 0.25%FS linearity, wide 12-45 V DC supply range and easy-mounting design make it a practical, dependable choice, backed by a 24-month warranty and direct manufacturer support. When the signal is small but the consequence is large, choose the transducer with the sensitivity to see it.