In order to make a digital device, first electrical signals are made with transducers or sensors from heat , pressure etc. The electrical signal is converted to an acceptable reading of the circuit connected to the signal conditioning circuit. Different types of transducers are used depending on the subject of measurement. The structure and nature of the signal conditioner depends on the signal received from the transducer. Microprocessors and even computers are used to process signals. LEDs, 6 segment displays , printers , chart recorders, etc. are used to display information.