Counter measures time interval, frequency, period

The SR620 universal time-interval counter, now available in the UK from TTi (Thurlby Thandar Instruments), measures time interval, frequency, period, pulse width and phase as well as rise and fall times.

The SR620 is a reciprocal interpolating counter.

The standard timebase is a 10GHz temperature-compensated oscillator with 3x10-9 per day aging.

An optional oven oscillator provides even greater accuracy with 5x10-10 per day aging.

For more demanding applications, a rear panel input allows connection of a 5 or 10MHz timebase.

Built-in statistical functions are provided in all modes.

These include mean, maximum, minimum, standard deviation and Allan variance.

An easy-to-read 16-digit LED display shows any of these parameters on sample sizes from one to one million.

The new instrument measures virtually any signal with a variety of arming and gating modes.

Intervals up to 1000 seconds in +/-time, +time or external (with or without holdoff) arming modes can be measured.

Frequency may be measured over 12 orders of magnitude.

The frequency range extends from 0.001Hz to 1.3GHz.

Pre-programmed frequency measurement gates include one period, 0.01, 0.1 and 1.0 sec, or external.

With an external trigger, gates may be programmed from 1us to 10ms. 'Start/stop' inputs range from -5 to +5V, and may be terminated at one megohm or 50 ohms.

Regardless of signal shape, duty cycle or amplitude, the SR620 allows fast measurement set-up.

The SR620 adds graphics to any measurement by displaying histograms and time-variation plots on any X-Y oscilloscope. Graphs may be sent to a plotter or printer.

GPIB and RS-232 interfaces are provided as standard for ATE and other applications.

An optional applications software package is also available.

Two DVM inputs (+/-2V or +/-20V full scale) and two D/A (+/-10V full scale) outputs on the rear panel allow DC voltages to be sent to and received by a host computer.

The SR620 costs £4975 (plus VAT).