Start with the Material You Need to Detect
Choosing a proximity sensor starts with a practical question: what do you need to detect?
Inductive sensors detect metal objects. Capacitive sensors can detect both metallic and non-metallic materials. Both provide detection without mechanical contact, but their operating principles make them suitable for different tasks.
When to Choose an Inductive Sensor
Inductive proximity sensors generate an electromagnetic field near the sensing face. When a metal target enters this field, the sensor detects the resulting change and switches its output.
Consider an inductive sensor for tasks such as:
- Confirming the position of a metal machine component.
- Detecting metal parts passing a sensing point.
- Checking whether a metal fixture is in place.
The installation environment also matters. Choose a model with housing, cable materials, and protection ratings suitable for the temperature, moisture, oil, or chemicals it may encounter.
When to Choose a Capacitive Sensor
Capacitive proximity sensors detect changes in capacitance caused by a nearby target. They can respond to materials such as plastic, glass, liquids, powders, and metal.
Possible applications include detecting non-metallic components and monitoring material levels. In suitable installations, a capacitive sensor can detect contents through a non-metallic container wall.
Detection depends on the material’s dielectric properties, target size, distance, and container construction. Sensitivity adjustment, where available, helps set the switching point for the application. Test the sensor with the actual target and container before final selection.
Compare the Two Technologies
| Selection Question | Inductive Sensor | Capacitive Sensor |
|---|---|---|
| What material needs to be detected? | Metal | Metal and suitable non-metallic materials |
| What is a typical task? | Metal component position detection | Non-metallic object or material level detection |
| Can it detect contents through a non-metallic wall? | Only if the target itself is metal and within range | Possible with a suitable material, wall, and setup |
| What needs particular attention? | Mounting conditions and sensing distance | Material properties and sensitivity setting |
Check the Installation Before Ordering
After choosing the sensing principle, confirm the available mounting space, working distance, supply voltage, output type, and connection method.
A rated sensing distance is measured under defined conditions. Use the manufacturer’s recommended operating distance and validate performance with your actual target. Allow for movement and installation tolerances instead of placing the target at the detection limit.
Find a Suitable YPROX Series
Explore the YPROX LJ and YP inductive sensor series for metal detection, or the DR capacitive sensor series for suitable metallic and non-metallic targets.
For selection assistance, contact YPROX with your target material, required sensing distance, installation details, and controller requirements.