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 maximum operating pressure of your system. This extra margin helps protect against unexpected pressure spikes or continuous pulses, which can occur in systems like water pressure or industrial process controls. These spikes might reach five or even ten times the normal maximum and could damage the sensor if not accounted for.

Continuous high-pressure pulses near or exceeding the sensor’s rated maximum can also reduce its lifespan. While increasing the sensor’s rating might seem like a solution, it often comes at the cost of reduced sensitivity and resolution. Using a buffer to dampen these spikes is an option, but it may slow down the sensor’s response time. So, finding the right balance between system requirements and sensor durability is key.

2. Q: What is the pressure medium?

A: Another critical factor when choosing a pressure sensor is the type of medium being measured. Is it a viscous liquid, a slurry, or something more corrosive? Or is it clean air, gas, or a non-reactive fluid? The compatibility of the sensor with the medium is essential to prevent corrosion, clogging, or degradation over time.

3. Q: What level of accuracy is required?

A: Accuracy refers to the degree of error in the sensor’s output, which can be influenced by factors such as nonlinearity, hysteresis, repeatability, temperature, zero offset, and humidity. Many manufacturers define accuracy based on a combination of these factors. However, real-world conditions like temperature fluctuations and zero drift can affect the actual performance of the sensor.

Higher accuracy typically means higher cost, so it's important to ask whether your application truly requires such precision. Using a high-precision sensor with low-resolution equipment can lead to inefficiencies. Always evaluate whether the accuracy you need aligns with your system’s requirements.

4. Q: What is the temperature range the sensor can handle?

A: Temperature plays a significant role in sensor performance. Most pressure sensors have two temperature ranges: the operational range and the compensated range. The operational range indicates the temperatures the sensor can withstand without damage, while the compensated range ensures that the sensor meets its specified performance criteria.

Temperature changes can cause zero drift and affect the full-scale output. Sensor specifications should clearly state these effects, such as ±x% full scale per °C or ±x% reading per °C. If this information isn't provided, it can lead to confusion about whether changes in output are due to pressure or temperature. Understanding these effects is crucial for accurate sensor use.

5. Q: What output type should I choose?

A: Pressure sensors typically offer various output types, including millivolt, voltage, milliamp, or frequency outputs. The choice depends on factors like distance between the sensor and control system, noise levels, and the need for signal amplification. For short-distance applications, a millivolt output is often sufficient and cost-effective.

If you need to amplify the signal, consider a sensor with a built-in amplifier. In long-distance or noisy environments, mA or frequency outputs are more suitable. In areas with high electromagnetic interference, additional shielding or filtering may be necessary to maintain signal integrity.

6. Q: What is the excitation voltage needed?

A: The excitation voltage depends on the sensor’s output type. Some amplified sensors include internal voltage regulators, allowing them to operate over a wide range of power sources. Others require a stable excitation source. Choosing the right power supply involves balancing system cost, stability, and performance requirements.

7. Q: Are interchangeable sensors important?

A: Interchangeability is crucial for OEMs and systems that require frequent sensor replacement. If sensors are interchangeable, you can replace them without recalibrating the entire system, saving time and reducing costs. This feature is especially valuable in mass production and maintenance scenarios.

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

A: All sensors tend to drift over time, so understanding their long-term stability is important. A sensor with good long-term stability reduces the need for frequent recalibration and minimizes future maintenance issues. It’s wise to select a sensor that offers predictable performance throughout its lifecycle.

9. Q: How robust is the sensor?

A: Robustness refers to the sensor’s ability to withstand harsh environments. Consider factors like mechanical strength, resistance to moisture, vibration, and impact. The housing material and sealing should be suitable for the intended application. Whether the sensor is used in a wet, dusty, or high-vibration environment, proper selection ensures reliability and longevity.

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

A: Most pressure sensors come with short cables, but for longer distances or complex installations, connectors may be necessary. Ensure that the sensor provides the appropriate cable or connector type to match your system’s requirements. Proper connection is essential for reliable data transmission and system integration.