Pressure sensor selection common sense - Solutions - Huaqiang Electronic Network

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1. Q: What kind of pressure is the sensor measuring?

A: The first thing to consider is the maximum pressure your system will experience. To ensure reliable performance, it's generally recommended that the sensor's pressure range be at least 1.5 times the system’s maximum pressure. This extra margin accounts for unexpected pressure spikes or continuous pulses, which can occur in systems like water pressure or industrial process controls. These spikes may reach five or even ten times the normal maximum pressure, potentially damaging the sensor. Continuous high-pressure pulses near or exceeding the rated limit can also shorten the sensor's lifespan.

While increasing the sensor's rated pressure might seem like a solution, it often reduces the sensor’s resolution. Using a buffer can help reduce the impact of spikes, but this introduces a trade-off by slowing down the response time. All pressure sensors are designed to endure up to 200 million cycles without performance degradation. Choosing the right sensor involves finding a balance between system requirements and long-term reliability.

2. Q: What is the pressure medium?

A: The type of medium being measured is a critical factor. Will it be a viscous liquid, a slurry, or a corrosive fluid? Is it clean air, or something more challenging like steam or gas? The material in contact with the sensor affects its selection, as some media may corrode or damage the sensor over time. It's important to choose a sensor that is compatible with the medium to avoid premature failure.

3. Q: What level of accuracy is required?

A: Accuracy refers to the sensor’s output error, which can be influenced by factors such as nonlinearity, hysteresis, repeatability, temperature, zero balance, and humidity. Many manufacturers define accuracy as a combination of these errors. However, real-world conditions like temperature fluctuations or power supply variations can further reduce the actual accuracy. High-accuracy sensors come at a higher cost, so it's important to ask whether your application truly requires such precision. Using a high-precision sensor with a low-resolution system is inefficient and unnecessary.

4. Q: What is the sensor’s temperature resistance?

A: Pressure sensors operate within specific temperature ranges. There are two main categories: working range and compensation range. The working range indicates the temperatures the sensor can withstand without damage, while the compensation range ensures that the sensor meets its specified performance under those conditions. Outside the compensation range, the sensor may still function but not at its full accuracy. Temperature changes can cause zero drift and affect the full-scale output. Sensor specifications usually include terms like ±x% full scale / °C or ±x% reading / °C. Understanding these parameters is essential to avoid confusion between pressure and temperature-induced errors.

5. Q: What output type should I use?

A: Common output types include millivolt, voltage, milliamp, and frequency. The choice depends on the distance between the sensor and the control system, noise levels, and whether you need signal amplification. For short distances, millivolt outputs are typically sufficient and cost-effective. If you need amplification, consider a sensor with a built-in amplifier. In long-distance applications or noisy environments, mA or frequency outputs are more suitable. In areas with high RF or EMI interference, additional shielding or filtering may be necessary to maintain signal integrity.

6. Q: What excitation voltage do I need?

A: The excitation voltage depends on the sensor’s output type. Some amplified sensors have internal regulators that work with a wide range of unregulated power sources. Others require a stable excitation source. Whether you use regulated or unregulated power will affect both performance and cost. It's important to select an appropriate power supply that matches the sensor’s requirements.

7. Q: Do I need interchangeable sensors?

A: Interchangeability is crucial, especially for OEMs. If sensors are interchangeable, you can replace them without recalibrating the entire system, saving time and reducing costs. This is particularly beneficial when sending products to customers, as it simplifies maintenance and repairs.

8. Q: How stable is the sensor over time?

A: Most sensors experience some degree of drift over time. Long-term stability is a key consideration, as it affects the sensor’s reliability and the need for frequent recalibration. Understanding this upfront helps prevent future issues and ensures consistent performance.

9. Q: How robust is the sensor?

A: Mechanical strength and environmental resistance are important. Consider the environment where the sensor will be used—will it be exposed to moisture, vibration, or impact? The housing material and design play a significant role in determining the sensor’s durability. Choosing the right enclosure ensures the sensor can withstand harsh conditions.

10. Q: How do I connect the sensor to my system?

A: Most pressure sensors come with short cables, but for longer distances, connectors may be necessary. Ensure that the cable length and connection type match your system’s requirements. Proper wiring is essential for reliable operation and signal transmission.