The manual collimator produced by Newheek is mostly used in photography. The opening and closing activities of this type of manual collimator shielding lead leaf are achieved by manually adjusting the knob or pull rod on the collimator. In addition to the aforementioned internal structure, it also has an irradiation field indication system. It uses an indicator light bulb to simulate the focus of the X-ray tube, replacing X-rays with visible light and reflecting them on the bed surface through the reflection of the reflector. The visible light path after reflection is the same as the light path after the X-ray penetrates the reflector, so it can indicate the size of the irradiation field in advance. Because the life of the indicator is relatively short, the lighting of the indicator is controlled by a button switch, which can be turned off within 15s~1min. Some indicator lights have two levels of brightness in order to meet the irradiation field indication when the indoor brightness is high. The reflector is generally made of silver-plated plastic with an aluminum equivalent of about 0.5mm, which will not affect the X-ray imaging. In front of the collimator is also installed a clean and transparent plastic plate with black lines or black dots engraved on it to indicate the center of the radiation field.
Some manual collimators are marked with the size of the irradiation field around the knob or within the movement range of the pull rod, which is mainly used for the irradiation field preset before the irradiation field indicator is lit, so that it can be faster after the indicator is lit. Adjust the size of the irradiation field to extend the service life of the indicator light.