Simple, Reliable Non-Intelligent Pressure Transmitter for Dependable Industrial Measurement

Not every pressure point needs a smart transmitter with menus and diagnostics. For thousands of pumps, compressors, machines and lines, what matters is a simple, rugged instrument that outputs a clean 4-20 mA signal year after year. The QWY-304 is that workhorse: no unnecessary complexity, no fragile features, just reliable pressure measurement in an IP67, 316L package.

Why Do You Need a Simple, Non-Intelligent Pressure Transmitter?

Intelligent transmitters bring configuration menus, digital protocols and diagnostic features, but they also bring higher cost, more training and more that can go wrong in harsh service. Many industrial pressure points do not need any of that: they need a dependable analog signal that a PLC or pump controller can read, at a price that makes sense for the application. A non-intelligent transmitter has no microprocessor to fail, no protocol to configure and no menu to navigate, which means fewer failure modes, faster replacement and simpler spares management. For OEM machines, remote sites and standard process loops, the simple transmitter is not a compromise; it is the right engineering choice, delivering exactly the reliability that the application demands.

Working Principle: Direct, Uncomplicated Signal Conversion

The QWY-304 measures pressure with a 316L stainless steel sensing element and converts it directly into a proportional 4-20 mA signal using straightforward analog conditioning, with no microprocessor between the sensor and the output. The result is a signal that is immediately readable by any PLC, controller or display, with nothing to configure beyond the factory-calibrated range. The transmitter offers linearity superior to 0.5%FS, covers measurement ranges up to 0-1000 psi, and is housed in an IP67-protected body with a DIN43650 connector and polythene cable. Its simplicity is its strength: fewer components, fewer failure modes, and a lifetime of dependable service.

Structural Advantages of the QWY-304

• Non-intelligent design: no microprocessor, no configuration, no protocol issues.
• IP67 protection: dust-tight and immersion-resistant for harsh environments.
• 316L stainless steel wetted parts: corrosion-resistant and long-lasting.
• Standard 4-20 mA output: universal compatibility with control systems.
• Linearity superior to 0.5%FS: dependable accuracy for industrial control.
• DIN43650 plug connector: quick, secure, widely available termination.
• NPT1/8 and NPT1/4 connections: standard industrial threads.
• Polythene cable: durable and flexible for field routing.

Pain Point Analysis: 4 Challenging Working Conditions

Application Cases

Product Advantages

• Non-intelligent design with minimal failure modes
• IP67 dust-tight, immersion-resistant protection
• 316L stainless steel wetted parts
• Standard 4-20 mA output, universally compatible
• Linearity superior to 0.5%FS
• DIN43650 plug connector for quick installation
• NPT1/8 and NPT1/4 process connections
• Measurement range up to 0-1000 psi
• Durable polythene cable
• OEM-friendly with fast delivery and support

Technical Parameters

SEO FAQ

Q1: What is a non-intelligent pressure transmitter?

A non-intelligent pressure transmitter is a simple analog instrument that converts pressure into a standard 4-20 mA signal without a microprocessor, digital communication or configurable menus. The sensing element and analog conditioning circuit produce an output that is directly proportional to pressure, factory-calibrated to the ordered range. This simplicity is intentional: there is nothing to configure, nothing to update and no protocol to fail. Non-intelligent transmitters are ideal for the vast majority of industrial pressure points, where a reliable analog signal is all that is required, and they are typically more economical and more robust than their intelligent counterparts.

Q2: Why choose a non-intelligent transmitter instead of a smart one?

Choose a non-intelligent transmitter when the application needs a dependable analog pressure signal and none of the smart features. Smart transmitters offer remote configuration and diagnostics, but they cost more, require training, and add electronics that can fail or lose configuration in harsh service. For pumps, compressors, machines and standard process loops, the simplicity of a non-intelligent transmitter means fewer failure modes, drop-in replacement without setup, and simpler spares management. Many plants standardize on non-intelligent transmitters for general duty and reserve smart instruments for critical loops where their features genuinely pay off.

Q3: What is the accuracy of the QWY-304?

The QWY-304 offers linearity superior to 0.5%FS, meaning the output deviates from an ideal straight line by less than 0.5% of the full-scale range. On a 16-bar transmitter, this corresponds to an error of less than 80 mbar across the entire span, which is entirely adequate for pump protection, machine monitoring, compressor control and most general industrial applications. Each unit is factory-calibrated at multiple points to verify linearity, and the calibration is stable over time thanks to the simple, robust analog design. For applications requiring higher accuracy, other models in our range offer up to ±0.1%FS.

Q4: What does IP67 protection mean in practice?

IP67 means the QWY-304 enclosure is completely protected against dust ingress (digit 6) and withstands temporary immersion in water up to 1 meter for 30 minutes (digit 7). In practice, this makes the transmitter suitable for wet pump rooms, outdoor installations, washdown areas and dusty industrial environments where moisture and particulates would damage instruments with lower ratings. The sealed housing protects the electronics and connections, reducing failures caused by condensation and water ingress. For an instrument that may spend its life in a damp valve pit or a hosed-down process area, IP67 protection is a decisive reliability feature.

Q5: What process connections are available?

The QWY-304 is available with NPT1/8 and NPT1/4 process connections, the standard tapered pipe threads used for pressure instruments throughout industry. NPT threads seal by the interference of the tapered thread form and are typically used with thread sealant tape. The 1/4" NPT size is the most common for industrial transmitters, while 1/8" NPT is used in compact manifolds and test equipment. Both options allow direct mounting on pipe tees, block-and-bleed valves and machine manifolds. If your application requires a different connection standard, please contact us to discuss available options.

Q6: How is the transmitter wired?

The QWY-304 uses a DIN43650 plug connector, the widely used industrial standard that accepts a mating plug with screw terminals. To wire the transmitter, connect the loop supply and the signal lines to the correct terminals in the DIN43650 plug, observing polarity, then push the plug onto the connector and secure it. The DIN43650 standard means replacement plugs and pre-wired cables are readily available from any electrical supplier. The polythene cable connected to the plug should be routed with a drip loop and secured with strain relief. For wet installations, ensure the plug gasket is in good condition to maintain sealing.

Q7: Can the transmitter be used with corrosive media?

Yes. The wetted parts of the QWY-304 are made of 316L stainless steel, which resists corrosion from a wide range of industrial media including water, oils, many chemicals and atmospheric exposure. This makes the transmitter suitable for water treatment, chemical plants, marine and food processing environments where corrosion resistance is essential. For media that attack 316L, such as concentrated strong acids at elevated temperature, please discuss the application with our engineers, who can recommend alternative wetted materials or a chemical seal arrangement to protect the instrument.

Q8: What is the maximum pressure range?

The QWY-304 is available with measurement ranges up to 0-1000 psi, covering the majority of industrial pressure applications from low-pressure processes to high-pressure hydraulic and pneumatic systems. The transmitter is factory-calibrated to the exact range ordered, with the 4-20 mA output mapped across that span, so the full output resolution is available over your working range. When ordering, specify your maximum operating pressure and the normal operating range, and our engineers will confirm the correct range selection, including the appropriate proof pressure margin for your application.

Q9: What maintenance does the transmitter require?

The QWY-304 is designed for maintenance-free operation in normal service. Periodically check the process connection for leaks, verify the DIN43650 plug is secure and its gasket is intact, and confirm the output against a reference measurement. The zero point can be checked by isolating the transmitter and venting it to atmosphere; the output should read 4 mA, and minor deviations can be corrected with the zero adjustment. In dirty processes, clean the pressure port during scheduled maintenance. Because there is no configuration to lose and no protocol to maintain, the transmitter is one of the lowest-maintenance instruments in the plant.

Q10: What support and delivery options do you offer?

We manufacture the QWY-304 and provide direct technical support including application advice, installation guidance and troubleshooting. OEM customers benefit from our flexible programs: custom ranges, custom connections, custom cable lengths, labeling and packaging, with a monthly supply capacity of 100 pieces and delivery within 5-8 working days. Every unit is factory-calibrated and tested before shipment, and calibration certificates are available on request. Contact us with your pressure range and connection requirements, and we will provide a quotation and delivery schedule promptly.

Why Choose Our Simple, Reliable Pressure Transmitter?

The QWY-304 is built for the engineer who values dependability over features. With no microprocessor to fail, no protocol to configure, IP67 protection and 316L wetted parts, it delivers a clean 4-20 mA signal year after year in the toughest general-duty service. As the manufacturer, we combine this simplicity with factory calibration, OEM flexibility and delivery in days. When your plant needs a pressure transmitter that simply works, choose the QWY-304.