Current Meter Counter Model CMC20A

The Model CMC20A is an enhanced version of our proven Model CMC20 which is used with the majority of mechanical current meters. The CMC20A is a self-contained instrument featuring microprocessor control circuitry, a quartz time base and a high temperature liquid crystal display.

The counter is powered by 6 x AA size alkaline batteries. Battery voltage below 5.8 volts is indicated by the display of decimal points. An internal buzzer sounds at each contact closure during the timing period to indicate correct operation.
The display on the CMC20A gives continuous indication of the pulse count during the course of the reading period - and indicates with a resolution of 1 to a maximum of 9999 counts.

Main Features

  • Accurate Timing - The timer starts at the first contact closure
  • User selectable contact debounce time
  • Counts up to 40 pulses per second
  • Battery voltage displayed on power up
  • High temperature LCD display
  • Designed to USGS specifications
  • Robust construction & adjustable neck strap
  • Housing: Submersible powder coated aluminium die cast case with nylon webbing adjustable neck strap.
  • Dimensions: 160 x 100 x 55mm (6.3" x 3.9"x 2.2")
  • Weight: 1 Kg (2.2 lbs)
  • Display: 4 Digit High Temperature liquid, crystal display rated to 80oC
  • Accuracy: ±0.1 seconds (Timed from first contact closure); ±1 pulse
  • Timer: Quartz crystal accuracy, better than 1 in 20,000.
  • Preset Facility: Time intervals of 10, 20, 30, 40, 50, 80, 100, 200 and infinity seconds.
  • Infinity Mode: INT. This mode is used for depth measurements with ground-feeler weights, manual operation of counter or integration measurements
  • Operating Temperature: -20°C to +70°C
  • Humidity: 0 - 100%
  • Contact Debounce: The current meter pulse is debounced in software. The debounce time is user selectable. (1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45mS) This is useful for a meter with a mechanical “cat whisker” contact wire.
  • Buzzer: Instantaneous beep for each current meter pulse except in the integrate mode - in this mode, the buzzer gives a continuous beep while the current meter switch or ground feeler weight switch is closed.
  • Power Supply: 9V DC - 6 AA Alkaline batteries (or 6 AA Nickel Metal Hybrid). The actual battery voltage is displayed for 2 seconds each time the unit is switched on. Low voltage is also indicated by all decimal points showing on the display at 5.8 volts.
  • Packed Dimensions: 260 x195 x 160mm (10.2"x7.7"x 6.3")
  • Packed Weight: 1.3 Kg (2.9 lbs)