Dual Channel Laboratory Counter

The GMS1800a can be used with industry standard Alpha and Beta detector drawer units (such as the AEA Technology I Harwell Instruments types ‘ADU’ and ‘SDU’, 0744, 0771 and 0772), or with other instruments providing digital pulse output signals.

The Laboratory Counter is a microprocessor based unit which may be used to count digital pulse signals over a range of user selectable counting periods. It is a compact and robust unit suitable for laboratory or field use.

GMS1800a is powered either by an internal rechargeable battery or externally by a mains supply unit, which recharges the battery at the same time. The instrument can also operate from a 12V DC source such as a vehicle battery, making it convenient for mobile field surveys.

The unit provides two counting channel inputs and displays the accumulated counts in each channel over a user- selected counting period. The unit may alternatively display the count difference between the two input signals.

  • Two independent counting inputs
  • Simple operation
  • Battery & mains power
  • Suitable for laboratory or field use
  • Output to computer or printer
  • User-selectable time interval
  • 50kHz maximum counting rate
  • Deadtime correction
  • Maximum count > 4×109
  • Robust metal case
Item Data
Inputs ‘ADU’ Alpha Drawer Unit & Type 0744, 956012
‘BDU’ Beta Drawer Unit & Types 0771,0772, 956025
Outputs RS232 for connection to a computer or printer
Maximum Rate 50kHz on each input
Maximum Count 4,294,967,295 (232⁻¹)
Duration Maximum (free running) count duration is 99,999 sec.
Repeat Automatic repeat counting operation up to 10 times, with individual count results retained for review
Dead time Provides dead time correction, using user defined dead time values
Alphanumeric Display 4 line 16 character LCD with LED backlight
Power Indicator Yellow lamp is lit when the instrument is powered
Counting Indicator Counting Indicator - A green lamp is lit when the instrument is counting, and the lamp flashes when the count is completed.
Power Supplies
Internal Maintenance-free lead acid battery
External Mains operation, 240VAC or universal input (110~240VAC) options
Vehicle 12V DC supply adapter for vehicle operation 2.1 mm DC power socket on rear panel
Main Buttons Two Control Buttons which are used together with menu captions shown on the display
Main Dial A rotary control selects the count duration (10, 30, 60, 100, 300, 600, 1000, 1800, 3600 seconds and free running), and also switches the instrument on.
Battery Battery isolation switch on rear panel
Life >10 hours battery operation with two drawer units connected
Status Battery voltage is shown on display
Environmental Protection IP 30
Temperature Range Temperature range +5°C to +40°C
Case Strong metal case made of aluminium sheet with cast front bezel, Two front feet can be extended for easy viewing
Size H100 mm (feet folded in), D200 mm, W230 mm
Weight 2.2 kg
Get in touch with The JCS team
Request JCS Certificates
Please let us know which certificates you need.