At present, different types of proximity sensors should be selected for different materials of detectors and detection intervals in order to obtain the cost-effective system. To this end, the following criteria should be followed when making a selection:
1. When the detection body is metal, a high-frequency oscillating proximity sensor should be used to detect iron-nickel and A3 steel most flexibly. Aluminum, brass, and stainless steel detector bodies offer less detection flexibility.
2. When the detection body is made of non-metallic materials, such as wood, paper, plastic, glass or water, capacitive proximity sensors should be used.
3. Photoelectric proximity sensors or ultrasonic proximity sensors should be used to detect and control metal bodies and non-metals at a distance interval.
4. When the detector body is metal but the flexibility requirement is not high, a low-cost magnetic proximity sensor or Hall proximity sensor can be used.
Elements of proximity sensor selection:
Detection type: built-in amplifier, separation amplifier;
Shape: round, square, trough;
Detection interval: mm;
Test object: iron, steel, copper, aluminum, plastic, water, paper, etc.;
Working power supply: DC, AC, AC and DC general;
Output mode: normally open (NO), normally closed (NC);
Output mode: two-wire, three-wire (NPN, PNP);
shielded and unshielded;
Lead-out type, adapter type, adapter relay type;
Response frequency: Multiple objects can be detected in one second