How to test surveillance cameras
The test surveillance camera mainly tests the resolution and color reproduction illumination backlight compensation, and secondly measures the minimum operating voltage of the spherical distortion power consumption. This article gives a brief introduction to the definition of resolution and color reproduction and illumination backlight compensation, so that you Understand what are the test elements of surveillance cameras. The picture below shows the test pictures of common surveillance cameras, which we also call test cards.
1. Monitoring camera resolution
When testing multiple surveillance cameras, the same lens should be used. It is recommended to make a fixed-focus two-variable lens. The center circle of the test card appears on the left and right sides of the monitor screen, and the given tick marks are clearly and accurately counted. There are 10 sets of vertical lines and 10 sets of horizontal lines in the left and right directions. Representing vertical and horizontal resolution, respectively, and the corresponding set of lines has been given. For example, when you see a higher value stripe, the higher the image resolution, the better the camera effect.
2. Surveillance camera color reduction test
First, observe the costumes of the characters from a distance, see if there is any color distortion, compare the objects with vivid colors, watch the sensitivity of the surveillance camera, and put the color album in front of the camera to see the clarity of the picture, too light or too thick, and respond to the movement again. The color object is photographed to see if there is a color trailing delay blur. The common test method is to put a pot of green plants in front of the test, which can test the color reproduction degree and beautify the environment.
3. Surveillance camera illumination test
The surveillance camera is placed in the dark room, and the active 220V self-igniting lamp is placed in front of and behind the dark room. A voltage regulator is arranged to adjust the voltage of the dark room to adjust the voltage of the dark room. The voltage can be adjusted from 0V to 250V. The indoor lighting can also be adjusted from the darkest to the brightest. When the camera aperture is turned to the maximum during the test, the next minimum illuminance value is recorded. The active light regulator is dimmed to the inside of the darkroom and the aperture is displayed. The minimum minimum illuminance value is recorded again, and the front and rear lights can be separately calibrated.
4. Surveillance camera backlight compensation test
There are two ways to test this parameter. In the dark room, turn on the front side of the surveillance camera to adjust the light to the brightest, then place a picture or text under the light, and bring the surveillance camera to the camera to see the image. Whether the text can be seen clearly, the picture is not glaring, and adjust the AL AX pull switch to see if there is any change, which effect is best. The other is to take the camera out of the window in a sunny situation, and see if the image and text can be seen clearly.
5. Surveillance camera ball distortion test
If the ball type is distorted, put the test card on the front of the surveillance camera so that the whole sphere appears on the screen. See if the sphere has an ellipse, move the camera forward, see if the center of the circle is enlarged, and then test the corner box for a long distance. Arc distortion and so on.
6. Surveillance camera power consumption test
The minimum operating voltage, use a multimeter to measure the current, use a small regulator to adjust the voltage.