What are sensors and how we test them?

From the smartphone that knows which way you're holding it to the factory line that builds it, our world hums with invisible intelligence. At the heart of this intelligence are sensors—the tiny, powerful "senses" of modern technology. But what exactly are they, and why is ensuring they work perfectly so critical? Let's break it down.

1. What is a Sensor?

Think of a sensor as a translator. According to the international standard ISO/IEC/IEEE 21451-1, a sensor is a device that converts a physical, chemical, or biological quantity (like heat, pressure, or light) into a useful electrical signal.

It does three key things:

• Senses: It "feels" something in the real world (temperature, movement, presence of a gas).

• Translates: It turns that "feeling" into a language machines understand: an electrical signal (a changing voltage, current, or frequency).

• Standardizes: It outputs that signal in a clean, predictable way so computers and controllers can use it.

In short, sensors are the essential bridge between our physical world and the digital systems that manage it.

Working Principle:

2. Where are Sensors Used? (They're Everywhere!)

You'd be hard-pressed to find a modern industry that doesn't rely on sensors.

Smartphones & Smart Homes: The auto-rotate screen? That's an accelerometer and gyroscope (governed by standards like IEEE 2700). Your smart thermostat adjusting the temperature? Thank a temperature sensor.

Cars & Transportation: From tire pressure monitors for safety to the radar and cameras enabling assisted driving, modern vehicles are packed with sensors.

Factories & Automation: Robotic arms use force and vision sensors to assemble products with precision. Sensors on pipelines monitor pressure and flow to prevent accidents.

Healthcare: Critical devices like MRI machines and everyday wearables like fitness trackers depend on highly accurate sensors to monitor health.

Energy & Power Systems (Our Special Focus): This is where our expertise shines. The entire electrical grid relies on sensors-specifically current and voltage sensors (like Instrument Transformers)—to monitor power flow, prevent outages, and ensure your electricity bill is accurate. If these sensors are off, the whole system's decisions are based on bad data.

3. The Main Categories of Sensors (Making Sense of the Types)

Sensors come in all shapes and for all purposes. For a clear overview, the most common way to categorize them is by what they measure.

By What They Measure (The Primary Input):

This is the most intuitive way to understand a sensor's job. Key categories include:

• Physical & Environmental: The largest group, measuring properties like temperature, pressure, position, speed/acceleration, flow, force, and light.

• Chemical & Composition: Detecting specific gases, humidity, moisture, or pH levels in air or liquids.

• Biological: Used primarily in life sciences and healthcare to measure parameters like blood glucose, heart rate, or specific biomolecules.

The Special Case: Electrical Sensors

Our core expertise lies here. Electrical sensors are a critical sub-category designed to measure electrical properties themselves. They are the "meters" inside every electrical and electronic system. The main types include:

• Current Sensors: The workhorses for monitoring power flow. They measure the magnitude of electric current, from tiny milliamp signals in circuits to massive currents in power lines. Current Transformers (CTs) are a classic and vital type.

• Voltage Sensors: Essential for system health and safety. They measure electrical potential difference (voltage), ensuring equipment operates within safe limits and providing data for power calculations. Voltage Transformers (VTs) or Potential Transformers (PTs) are key examples.

• Power & Energy Sensors: These often combine current and voltage measurement to calculate real power (Watts), apparent power (VA), and energy consumption (kWh)—fundamental for efficiency analysis and billing.

• Field & Signal Sensors: Measure fundamental electromagnetic properties, such as magnetic field strength (using Hall effect sensors) or specific signal frequencies and waveforms.

Why This Focus Matters:

For electrical sensors, their output signal is the direct measurement. Therefore, the accuracy, stability, and speed of this signal are non-negotiable. A slight error in a current reading can lead to a cascade of issues—from incorrect billing to catastrophic system failure. This makes their performance verification through precise testing not just a technical step, but a cornerstone of system reliability and safety.

With the critical role of electrical sensors established, how do we ensure they perform flawlessly? Is there a method to efficiently and accurately test this diverse family of devices? This is the core challenge our solutions are designed to address.

4. Tunkia's Solution for Sensors Testing

The required testing for sensors includes general inspection, metrological performance, safety performance, mechanical performance, environmental adaptability, and EMC experiments. Tunkia's products primarily focus on the testing of metrological performance, offering complete metrological performance testing solutions. Moreover, the testing technology covers the entire manufacturing process of sensors, playing a crucial role in their design and quality control. Specifically, metrological performance testing includes:

Static Performance: Basic error, zero-point output error, linearity, hysteresis, repeatability, etc.

Dynamic Performance: Response time, frequency bandwidth, phase shift, etc.

Influence Tests: Auxiliary power influence, load voltage influence, etc.

Our solution defines not only what to test, but also solves the practical challenges of how to test with accuracy, speed, and completeness, truly empowering your R&D and production. The key advantages lie in:

• The High-Current Source System

Accurate testing begins with accurate excitation. Tianheng provides an industry-leading, complete high-current source solution to ensure authentic and precise test conditions.

Full-Spec Coverage: Outputs include DC, AC, and integrated AC/DC, meeting diverse testing needs from DC current sensors to high-frequency response sensors.

Dedicated & General Solutions: We offer both general-purpose current sources for various metrology applications and specialized solutions for sensor manufacturers, such as the TI2000 High-Current DC Standard Source.

• Multi-Station Parallel Testing Support

Designed with production-line efficiency in mind, our solution integrates parallel processing and fast response.

Test Multiple Sensors at Once: Standard solutions support 2-4 stations for parallel testing, while customized configurations can be scaled to over 64 stations. Combined with dedicated fixtures and secondary signal testers, this multiplies testing throughput.

Ultra-Fast Dynamic Response: To keep pace with production cycles, our DC sources feature extremely fast settling times, reaching full-scale output stability in < 0.5 seconds. This dramatically reduces per-unit test time, eliminating wait states for high-efficiency testing.

• Comprehensive Test System

Built on years of industry expertise, we offer a highly integrated testing framework that delivers a complete performance profile in a single setup.

Extensive Parameter Coverage: One system evaluates everything from static parameters (basic error, linearity, hysteresis) to dynamic parameters (bandwidth, response time) and influence factors (power consumption, temperature coefficient).

One-Connection, Multi-Test Process: The integrated approach eliminates data silos and operational complexity caused by using multiple, disconnected devices. "Connect once, test all items" — significantly improving test consistency and data management efficiency.

In short, Tunkia's solution brings together precise testing signals, efficient multi-sensor testing, and a complete evaluation system in one smooth workflow. This means you can trust your sensor data—and move faster from design to delivery.

If you're interested in how our testing solutions can support your projects, we'd love to hear from you.