At present, various forms of infrared detectors in the security market are dazzling, overwhelming, uneven and inexpensive. How to choose a product with good cost performance? How to test it under family conditions?

1. Detection Range Testing - Installation of Detectors in accordance with Instructions

A. Distance test: The longest distance measured by the normal walking pace of human body (about 0.35-0.8 meters) should meet the requirements of its instructions.

B. Level (sector) angle test. From left to right, the human body moves from non-detection area to detection area, with an alarm indicator point of A, and from right to left, from non-detection area to detection area, with an alarm indicator point of B. Measuring point A and point B is the detection angle of its horizontal sector. It should meet the requirements of its instructions.

C. Vertical (vertical) angle test. Under the detector, the human body moves from left to right from the non-detection area to the detection area. The alarm indication point is point A, the upper part of the detector moves by hand, the left to right from the non-detection area to the detection area, and the alarm indication point is point B. The two points A and B are the vertical detection angles. It should meet the requirements of its instructions.

2. Detection Speed Testing - Testing in accordance with the specifications (0.30-3 m/s stipulated in the national standard)

A. Slow speed test: The human body moves at 70% of the detection distance at 30 cm step per second, and should have an alarm instruction. If there is no indication that the detection sensitivity is too low, there is a hidden danger of missing the report.

B. medium speed test: the human body moves in steps of 50-75cm per second, with alarm indication. If there is no indication, it indicates that it has a fault or low sensitivity.

C. Quick test: The human body passes through the detection range at a speed of 3 meters per second. There should be an alarm instruction if there is no indication of malfunction or low sensitivity.

D. Ultra-slow test: The human body moves at a speed less than 30 centimeters per second (about 20 centimeters). There should be no warning instructions. If there is an indication that the detection sensitivity is too high, it is easy to cause false alarm. The detection sensitivity can be adjusted appropriately.

E. Ultra-fast test: Use your hand in front of the detector 20-30 centimeters at a speed of 0.5 seconds, there should be no alarm instructions. If there are alarm instructions indicating that the detector sensitivity is too high or the internal time program circuit is not properly designed, it is easy to cause false alarm. It can be adjusted to reduce the detection sensitivity and then repeat the test.

3. Anti-interference ability test

A. The detector should be directed to a space without interference source, preferably at the window upstairs (as long as the sunlight does not directly shine on the detector, there is no floating object in the detection range, and no space passed by by by anyone). Connect the memory alarm indicator circuit or the sound circuit, carry out more than 24 hours of test, and no alarm should occur. If there is an alarm, it shows that the detector has poor anti-interference ability such as infrared spectrum change and air flow change.

B. Turn a desk lamp 60W directly to the detector at a distance of 60cm, turn on/off the lamp frequently, and the detector should not appear alarm instructions. If it appears, it shows that the detector has poor ability to resist strong light interference.

C. Place the same typhoon fan in the "strong wind" gear and the "shake head" gear 1.5 meters away from the detector, shake head to blow back and forth, and the detector should not appear alarm instructions. If there is an indication that the anti-air interference ability is poor.

D. There should be no alarm instructions when the mobile phone will be connected to the detector at a distance of 50 cm. The alarm indication beyond 50 cm indicates that the anti-interference ability of radio wave is poor.

E. Simulate a black object the size of a cat and move fast or slowly within the detection range without warning instructions. An alarm instruction indicates poor pet protection.

F. Temperature compensation test: In summer, when the ambient temperature rises to 30-32 degrees Celsius, the detection distance is tested. If the detection distance is shortened by more than 1/3, the temperature compensation is not good. Many imported products are difficult to pass.

How to avoid false alarm and missed alarm of infrared detector

1. Avoid false alarm

1. Do not place heated objects in the detection area, such as heating, water heater, TV, computer, refrigerator and other electrical appliances, unless they are turned off. Heaters, water heaters, computers and refrigerators will turn on and off when the automatic program control status meets, which will cause false alarms.

2. Avoid strong illumination interference within the detection range, such as sunlight, automobile light, spotlight and illumination. These light sources are rich in infrared spectra, which can cause false alarms.

3. Avoid objects that are drifting by the wind in the detection area, such as curtains, clothing, flowers and plants. Close windows and doors to avoid false alarm caused by air convection before deployment. Because the moving object cut the infrared ray, the detector misjudged.

4. Avoid animal interference within the detection range, and adjust the down-sounding area so that animal activities below 0.5 meters are not in the detection area. With a pet in the family, the multi-area detector can be replaced by a horizontal detector. The simplest way is to stick opaque tape to the bottom of the lens.

5. Find out the false alarm detector, find out the reason and eliminate it. Usually within the scope of anti-theft detection, the detection sensitivity can be fine-tuned to moderately reduce the detection distance.

6. Select detectors that are qualified by the Ministry of Public Security and have good cost performance.

2. Avoiding Leakage of Alarm

1. Obstacles should not be blocked in the detection area, and the detection gap is not enough to cause alarm.

2. The detection range and the direction of human activity are in the form of crossing (see the figure of human activity direction of arrow A). Don't face the direction of human activity directly (see figure of human activity direction of arrow B). 3.