A time-encoder-type meter for measuring capacitance and inductance

The instrument described here is essentially a time-encoder, which directly gives a digital read-out of capacitance, inductance or resistance, by measuring the transient response of an RC or RL circuit to a step-voltage input. This simple device can easily achieve high accuracy, which mainly depends upon three resistance standards. Time-encoding permits fast measurement, and impressively wide range, covering several decades, substantially independent of the dissipation factors of capacitance or inductance. It can be used as a laboratory instrument or for batching operations in the mass manufacture of electronic components and sampling reactive transducers on board an instrumented space vehicle. High speed of measurement and availability of digital read-out make it fit ideally into computer interfaces. Problems peculiar to the device in sampling applications are discussed in detail.