The sensitivity, detection range and installation height of the detector have a direct relationship to a large extent. The optimal installation height of a typical passive infrared detector is 2.1m to 2.5m. If it is a pet-proof detector, then it has a mounting height. The demand will be higher. If the installation is too high, the blind spot will be large. If it is too low, it may not be able to detect the far position. Therefore, the actual application also needs to be measured.
For example, a curtain detector that belongs to the principle of passive infrared, if it needs to be installed on a window, the installation height at this time is 25CM away from the window sill. If it is too high, people can drill it from under the probe if the distance is too low. May be crossed from above.
The principle of passive infrared is to monitor the temperature difference. When the outside temperature is about 37 degrees, it basically fails, so do not install near the heat source. In addition, it is necessary to pay attention to avoid fluidity areas such as vents, air conditioners and radiators that can change the ambient temperature, and also to block the shielding of the middle shield (even if it is transparent, such as glass).
Also, avoid moving objects such as fans, drying clothes, and curtains. Places where animal activity is frequent should also be avoided. If it is difficult to avoid the actual needs, then special attention should be paid to using a pet-proof detector.
Sensitivity is the most direct factor affecting the detector's false alarm rate or false negative rate. How to adjust the sensitivity so that the false alarm rate and false negative rate achieve the desired effect?
In conventional detection technology, sensitivity is a contradiction between false positives and false negatives. To reduce false positives, sensitivity is lowered, which will inevitably lead to an increase in false negatives. Conversely, in order to reduce false negatives, sensitivity is increased. It will also raise the issue of false positives. It is difficult to accurately grasp this "degree" in practical applications.
The specific setting of sensitivity depends on the actual environment. In general, if the application environment is rather harsh, for example, there are often birds or blade floats blocking the beam, it should be set in a low-sensitivity range. The active infrared detector should choose the appropriate response time: if it is too short, it will cause unnecessary disturbances, such as flying over small birds, passing through small animals, etc.; too long will result in missed reports. The shortest shading time is usually determined at a speed of 10 meters per second.
Main business: home burglar alarm , intelligent burglar alarm, GSM burglar alarm , infrared alarm, wireless burglar alarm
For example, a curtain detector that belongs to the principle of passive infrared, if it needs to be installed on a window, the installation height at this time is 25CM away from the window sill. If it is too high, people can drill it from under the probe if the distance is too low. May be crossed from above.
The principle of passive infrared is to monitor the temperature difference. When the outside temperature is about 37 degrees, it basically fails, so do not install near the heat source. In addition, it is necessary to pay attention to avoid fluidity areas such as vents, air conditioners and radiators that can change the ambient temperature, and also to block the shielding of the middle shield (even if it is transparent, such as glass).
Also, avoid moving objects such as fans, drying clothes, and curtains. Places where animal activity is frequent should also be avoided. If it is difficult to avoid the actual needs, then special attention should be paid to using a pet-proof detector.
Sensitivity is the most direct factor affecting the detector's false alarm rate or false negative rate. How to adjust the sensitivity so that the false alarm rate and false negative rate achieve the desired effect?
In conventional detection technology, sensitivity is a contradiction between false positives and false negatives. To reduce false positives, sensitivity is lowered, which will inevitably lead to an increase in false negatives. Conversely, in order to reduce false negatives, sensitivity is increased. It will also raise the issue of false positives. It is difficult to accurately grasp this "degree" in practical applications.
The specific setting of sensitivity depends on the actual environment. In general, if the application environment is rather harsh, for example, there are often birds or blade floats blocking the beam, it should be set in a low-sensitivity range. The active infrared detector should choose the appropriate response time: if it is too short, it will cause unnecessary disturbances, such as flying over small birds, passing through small animals, etc.; too long will result in missed reports. The shortest shading time is usually determined at a speed of 10 meters per second.
Main business: home burglar alarm , intelligent burglar alarm, GSM burglar alarm , infrared alarm, wireless burglar alarm
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