Laurel Time Interval Meter

The Laurel A-to-B Time Interval Meter can display pulse width or time delay between individual pulses to a resolution of 0.2 µs. sIt can also display average pulse width or average time delay between multiple pulses.
Time interval is measured between inputs on channels A and B. Timing starts when a pulse is applied to Channel A (selectable positive or negative edge), and ends when a pulse is applied to Channel B (selectable positive or negative edge). In case of a single pulsed signal, the A and B inputs can be tied together. A positive or negative slope may be selected to start timing, and the opposite slope must be selected to stop timing. Timing is achieved by counting 5.5 MHz clock pulses. Multiple integral time intervals are averaged over a gate time which is selectable from 10 ms to 199.99 s and also controls the display update time.

Time interval can be displayed in seconds, milliseconds, or microseconds with 6-digit resolution. In the typical application, time is displayed in milliseconds with 1 µs resolution. For times less than 100 ms, display resolution down to 0.2 µs can be achieved by applying a multiplier of 10, moving the decimal point by one position, and averaging many time intervals.

Highly accurate rate can be displayed by taking the inverse of time. Extensive arithmetic capabilities allow display in engineering units, such as meters/sec. Rate based on time requires use of the Extended vounter main board.

The FR dual-channel signal conditioner board accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from 12 mV to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions. A built-in isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.

Key Features

For periodic events with width from 1 µs to 199.999 s
Display resolution to 0.2 µs
Rep rates to 250 kHz
Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac
Trigger on positive or negative pulse edges
6-digit red or green LED display

Standard Features

Isolated 5, 10 or 24 Vdc excitation output to power sensors
Universal AC power, 85-264 Vac
External controls for reset, meter hold and decimal points
NEMA 4X, 1/8 DIN case

Extended Features

All capabilities of Standard Timer, plus rate based on 1/time.

Options

Serial communications: Ethernet Interface, Ethernet-to-RS485 server, USB Interface, USB-to-RS485 server, RS485 interface (dual RF11), RS485 Modbus interface (dual RJ45), RS232 interface.
Low voltage power: 10-48 Vdc or 12-32 Vac
Relay outputs: 2 or 4 relays, contact or solid state
Analog output: isolated 4-20 mA, 0-20 mA, 0-10V, -10 to +10V