Passive pyroelectric infrared sensor working principle and features:

  the human body has a constant body temperature, generally 37 degrees, it will issue a specific wavelength of about 10UM infrared, passive infrared sensor that is emitted by the human body to detect the infrared 10UM carried out about the work. 10UM launched around the human body through the infrared filter to enhance the Philippine soil after the Seoul gathered to the infrared sensor source. Infrared sensor sources commonly used pyroelectric element, this element in the received infrared radiation temperature changes will be lost when the charge balance, and external release of charge, follow-up testing after treatment by the circuit can generate alarm signal.

  1) of this probe is based on detection of human radiation as the target. Therefore, the pyroelectric element to the wavelength of about 10UM to be very sensitive to infrared radiation.

  2) In order to infrared radiation on the human body is only sensitive to radiation in its face to face is usually covered with a special mud Dole Philippines filters, interference from the environment under the control of apparent effect.

  3) passive infrared sensor, the sensor consists of two series or in parallel with each other pyroelectric yuan. And two electrodes made of the direction of the contrary, the environmental background radiation on the two pyroelectric elements is almost the same role, to produce pyroelectric effects cancel each other out, so probe no signal output.

  4) Once the person intrusion detection area, infrared radiation through the part of the mirror focus, pyroelectric element was received, but the two pyroelectric element to the heat received is different pyroelectric different, can not be offset by signal processing and alarm.

  5) Philippine mud Seoul filter according to the performance requirements are different, have different focal length (sensing distance), resulting in different monitoring field, depending on the field more and control more tightly.

Passive pyroelectric infrared probe the strengths and weaknesses:

Benefits:

Itself is not made any type of radiation, the device power consumption is very small, subtle is good. Low price.

Disadvantages:

◆ more vulnerable to heat, light interference

◆ Passive infrared penetration is poor, the body's infrared radiation easily be blocked, can not easily be received probe.

◆ susceptible to interference from radio frequency radiation.

◆ ambient temperature and body temperature close to, the detection and sensitivity decreased, sometimes resulting in short-term failure.

Anti-jamming performance:

1. Anti-jamming small animals

Detector installed in the recommended use of the height of the surface of the detection range of the mainland to small animals, generally do not generate alarms.

2. Anti-electromagnetic interference

Anti-electromagnetic interference detector performance requirements in line with GB10408 in 4.6.1, the general mobile phone electromagnetic interference will not cause false positives.

3. Anti-Light Interference

The sensitivity of detectors in the normal range by 3 meters from the H4 halogen light irradiation through the glass and do not produce alarm.