Precautions in the use of infrared lights One: infrared lights in the installation, debugging, must carefully browse the product manual, because the different manufacturers of technical parameters are different, IR Illuminator can not be assumed to be equipped with power and installation debugging.
Precautions in the use of infrared lamps two: the operating current of the infrared tube is very sensitive to the supply voltage, according to the product specification requirements, the use of switching power supply, not to increase the infrared lamp power supply voltage to increase the radiation power of infrared lamp, so it is likely to cause infrared lights burned; such as the use of ordinary DC power supply, IR Illuminator it is possible because of voltage instability, caused by infrared light is not enough, or because the voltage is too high to burn
Precautions in the use of infrared lights Three: the use of centralized power supply television monitoring system, the front-end equipment supply to the scientific design. Because the length of the cable is different, the DC voltage attenuation is different. When the distance between the infrared lamp and the control room is large, the power supply voltage of the infrared lamp near the control room may be high, IR Illuminator and the power supply voltage of the infrared lamp far from the control room is lower than that of the $literal. Coupled with the power supply voltage adjustment on the deviation, may cause the high voltage of the infrared lamp life shortened or even burnt out, low voltage of the infrared light emitting power is insufficient. Therefore, it is recommended to use a one-to-one power supply for infrared lamps as far as possible.
The use of infrared lights in the process of attention to four: In addition to the matching, but also to take into account the following factors, the selection of infrared lamp, IR Illuminator when the infrared light irradiation distance.
(1) The minimum illumination given by the camera. What is the minimum illumination concept here? The video signal produced by the camera has a nominal value of 1V, the standard value is 0.7V, and the video signal value of the minimum illuminance is $number standard. So the camera's image at the lowest illumination level will never be "like the Day".
(2) The camera in the minimum illuminance produced by the image definition, is using the television signal Test card to measure, its black and white stripes, require black reflectivity of nearly 0, white reflectivity is greater than 89.9. We sometimes do not have such conditions in situ observation, IR Illuminator such as: leaf and grassland reflectivity is very low, contrast is very small, it is difficult to obtain clear images.
(3) Give the camera the minimum illuminance, but also give the required value of f, the zoom lens generally gives only the maximum value of the 1 F, that is, the minimum value of the aperture f (the maximum of the actual size of the aperture), Ff D, then the D is fixed, and when the F focal length is 10 times times larger, F becomes very large (i.e. the aperture actual size becomes small). Luminous flux will be greatly affected.
(4) In the use of automatic aperture lens, automatic gain control or automatic electronic shutter camera, lens aperture f value will also change. For example, IR Illuminator the camera near the scene, reflection back to the strong light to the camera, or near a light camera, then the camera sensitivity will be reduced, the size of the automatic aperture will be shut small, luminous flux will be greatly affected.
(5) The effect of the shield on the infrared light is also affected, and in the transmission process, the transmittance and reflectivity of the infrared light are different through different mediums. Different window glass, especially the automatic defrost coating glass, the attenuation of infrared light is also different.
(6) Some equipment production or the seller, IR Illuminator does not give the infrared light the irradiation distance, only give the number of power, this may be less trouble for production, vendors, but this is very vague concept, because power consumption in addition to converting to infrared light, there are also power supply heat loss, circuit heat loss, light source heat loss, filter glass infrared efficiency and so on. The same power of the infrared lamp, the radiation distance may be far apart.