Chemical level measurement device with easy action cover and single

Abstract

This device measures the level of a certain chemical in a liquid infiltrated into a piece of test paper impregnated with a test chemical the optical properties of which alter according to the level of the certain chemical. It includes: a test paper holder, provided in a test paper insertion unit provided in a casing; a device for emitting light and a device for sensing light, both provided to oppose a piece of test paper held by the holder; a cover, slidably mounted to the casing, for selectably covering over the insertion unit; a device for biasing this cover in one direction; a device for engaging this cover in an extreme position in the opposite direction; and a device for releasing the engagement of the engaging device. This engagement releasing device may be a press button provided to the casing; and the sliding direction of the cover may be its opening direction of movement, or alternatively may be its closing direction of movement. Alternatively, this device may include a device for emitting light and a device for sensing light, both provided to oppose a piece of test paper, and a switch for selecting between an action mode for executing a measurement action and at least one other mode for performing some other function, these modes being switched between every time this mode selection switch is actuated. Optionally, at least three such modes may be switched between in a cyclical sequence. The mode selection switch may include a mode selection button.