Patient scales designed as stand-alone units to be placed on the floor. These scales are either mechanical (e.g., using springs) or electronic; they usually include the meter or display as an integral part. Most floor scales have a weighing capacity of up to 135 to 160 kg (300 to 350 lb) and a readability of 0.25 to 0.5 kg (0.5 to 1 lb); some electronic models can weigh up to 360 kg (800 lb). These scales are mostly used for diagnostic and weight control in physician's offices, field work, and at home. Typically, the scale platforms are manufacturer mechanically (include a balance beam mechanism with two poise bars) or electronic (include a sensor (e.g., strain gauge) and electronic circuitry to process the signal and display it as weight).