Time Interval Meters
Features
- Available in three digit heights: 0.56″ for panel mounting, 5.0″ (Mighty-5) for long-distance viewing.
- For periodic events from 1 µs to 199.999 s
- Display resolution to 0.2 µs
- 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
- Isolated 5, 10 or 24 Vdc excitation output to power sensors
- Green or red LED display
- Choice of isolated plug-in options for control and computer interface:
dual relays, 4-20 mA & 0-10 V analog output, RS232/485 serial I/O, low voltage AC & DC power - 1/8 DIN case environmentally sealed to NEMA-4X from front panel
- 1/8 DIN version certified to UL 3101-1, CAN/CSA-C22.2, EN 61010-1 (CE Mark)
Description
A-to-B Time Interval Mode
The Micro time interval meter can display pulse width or time delay between individual pulses. It 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.
The Micro time interval meter uses the FR dual-channel signal conditioner board and the standard (non-extended) counter main board.
Display
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.
Universal Signal Conditioner
The dual-channel signal conditioner used for pulse detection 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.
Built-in Flexibility
Plug-in isolated analog output, dual setpoint controller, and RS232/485 serial communications boards can upgrade the Micro and Mighty Series time interval meters from a stand-alone display to system interface and control. In particular, the meters can output an isolated 4-20 mA signal which tracks elapsed time.
Micro Series meters can be powered from 95-240 Vac ±10% and 95-370 Vdc, or optionally from 12-34 Vac and 10-48 Vdc. Any setup functions and front panel keys may be locked out for simplified usage and security. The popular 1/8 DIN version with 0.56″ high digits is environmentally sealed to NEMA-4X (IP65) from the front when panel mounted, and is available with red or green LEDs. All power and signal connections are via plug-in screw-clamp connectors.
Specifications
| Display | |
| Readout | 6 digits, 7-segment |
| Digit Height | Available with 0.56", 1.0", 4.0" or 5.0" digits. |
| Color | High brightness red. Green available with 0.56" digits. |
| Range | -999999 to +999999 |
| Indicators | Four LED lamps |
| Inputs | |
| Types | AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups |
| Grounding | Common ground for channels A & B |
| Channel A Frequency | 0.005 Hz to 1 MHz |
| Channel B Frequency | 0.005 Hz to 250 kHz |
| Selectable Hysteresis | -12 mV to +12 mV, +30 mV to +60 mV, -30 mV to -20 mV, |
| -150 mV to +150 mV, +350 mV to +600 mV, -600 mV to -350 mV, | |
| -1.15 V to +1.15 V, +1.25 V to +2.1 V, -2.1 V to -1.25 V | |
| Rolloff Filter | Selectable: 1 MHz, 30 kHz, 250 Hz. |
| Debounce Time | Selectable: 0, 3, 50 ms |
| Time Interval Mode | |
| Timing Start | Channel A pulse, + or - edges |
| Timing Stop | Channel B pulse, + or - edges |
| Periodic Timing | Gate time + 30 ms + 0-2 time intervals |
| Interval | Selectable 10 ms to 199.99 s |
| Gate Time | Selectable 10 ms to 199.99 s |
| Timeout | Same as periodic timing interval |
| Resolution | |
| 0 - 199.999 s | 1 ms |
| 0 - 99.9999 s | 100 µs |
| 0 - 9.99999 s | 10 µs |
| 0 - .999999 s | 1 µs |
| 0 - .099999 s | 0.2 µs |
| Accuracy | |
| Time Base | Crystal calibrated to ±2 ppm |
| Span Tempco | ±1 ppm/°C (typ) |
| Long-term Drift | ±5 ppm/year |
| Power | |
| Voltage, std. | 95-240 Vac ±10% and 95-370 Vdc |
| Voltage, opt. | 12-34 Vac and 10-48 Vdc |
| Frequency | DC or 49-440 Hz |
| Power isolation | Safety-rated to 250 Vac, meter ground to earth ground, |
| DC to 60 Hz, 4.2 kVp per High Voltage Test |
| Excitation Output | |
| 5 Vdc | 5 Vdc ±5%, 100 mA max |
| 10 Vdc | 10 Vdc ±5%, 120 mA max |
| 24 Vdc | 24 Vdc ±5%, 50 mA max |
| Output isolation | 50 Vdc to meter ground |
| Environmental | |
| Operating | 0°C to 60°C |
| Temperature | -40°C to 85°C |
| Storage Temperature | 95% at 40°C, non-condensing |
| Relative Humidity | NEMA-4X (IP-65) when panel mounted |
| Protection |
| Electrical Connections |
 |
Applications
Time Interval Mode for Time Delay
For periodic pulses applied to A and B channels, time delays can be measured down to 0.2 µs resolution from the rising or falling edge of A to the rising or falling edge of B (selectable).
Time Interval Mode for Pulse Width
The width of periodic pulses (t1 or t2) can be measured by tying the A and B channels together. As for time delay, readings are averaged over a user-selectable gate time.
Timing Process Dynamics with a Panel Meter and Time Interval Meter
The start and stop pulses used for timing can be generated by the dual relay board in a Micro panel meter or digital counter. For instance, the start and stop pulse edges can be created as temperature passes two alarm setpoints, or temperature cycles in a hysteresis control mode.
Replacing an Oscilloscope with a Micro Time Interval Meter
An oscilloscope is great for viewing and timing pulses in a lab. However, in fixed installations where digital timing accuracy and control outputs are required, a low-cost Micro time interval meter will be the instrument of choice. Resolution to 0.2 µs is feasible.
Instrumenting a Pulsed Laser System Using Micro Counters
The diagram below illustrates some of the many possibilities in instrumenting a pulsed laser system with Micro dual-channel counters: elapsed time, number of pulses, pulse width, pulse separation, duty cycle, and pulse rep rate.
