the lightmeter model ca813 is a portable, easy-to use instrument which features optical sensors that are designed to match the response of the human eye, making them ideal instruments for workspace analysis and planning. The ergonomically designed case, large display and intuitive function selection make this instrument the right choice for any application. The lightmeter model ca 813 is designed for simple one-hand operation. It provides selectable lux or foot-candle units for display and features a 3 1/2 digit backlit lcd and hold function. The model ca 813 offers a peak function.