GMS1800b | JCS Nuclear Solutions

The GMS1800b Laboratory Counter can be used with most common types of Geiger or Scintillation radiation detectors.

Measurement results are displayed on a large backlit LCD display. The Laboratory Counter also provides an audible indicator, which emits short clicks at lower count rates, and may also be used as an alarm indicator in rate meter mode.

The Laboratory Counter may also be used to count digital pulse signals from standard Alpha and Beta detector drawer units (such as the AEA Technology types ‘ADU’ and ‘BDU’, 0744, 0771 and 0772), or from other instruments providing digital pulse output signals. Two independent digital inputs are provided.

The GMS1800b Laboratory Counter 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.

Features at a glance

Two digital inputs for AEA drawer units
Input for Scionix CdTe probe
Battery & mains power
Suitable for laboratory or field use
Output to computer or printer
User-selectable time interval
User-selectable count limit Dead-time correction
Variable HT voltage 300V-2000V
Ratemeter function with bar graph display and audible alarm
Probe set-up parameter library
Audible indicator & headphone output
Robust metal case
Auto plateau plotting

Specifications

Item	Data
Inputs
	Geiger & Photomultiplier detector (SHV connector and optional PET100 connector).
	AEA Drawer Units ADU, BDU, 0744, 0771, 0772, 956012 (alpha), 956025 (beta) and compatible probes (9-pole D connector).
	Digital Inputs - TTL and RS422
	Scionix CdTe Probe (LEMO connector) Outputs
	RS232 for logging results to a computer or PDA. All counting results are output via the RS232 port, and each result is assigned a unique identification number.
	HT voltage 20V – 2000V 0.5mA.
Counting & Timing
Max count rate	All inputs: 150kHz
Max Count	4,294,967,295 (232–1).
Duration	Maximum (free running) count duration is 99,999s.
Repeat	Automatic repeat counting operation up to 10 times, with count results retained for review, or up to 250 times, with count results logged via the RS232 port.
Dead-time	Dead-time correction using user-selectable dead-time values, and background subtraction.
Indicators
Alphanumeric Display	4 line 20 character LCD with LED backlight.
Power Indicator	Yellow lamp is lit when the instrument is powered.
Counting Indicator	Green lamp is lit while counting, flashes when the count is completed.
HT Indicator	Red lamp is lit when HT voltage is on.
Configuration Control	PIN-code access control on configuration settings.
Controls
Main Buttons	Three control buttons used together with menu captions shown on the display.
Selector Switch	Selects the counting time, or Count limit, or ratemeter time-constant, and also switches the instrument on.
A rotary control	Adjusts HT voltage & other set-up values.
Battery	Battery isolation switch on rear panel.
Power Supplies
Internal	Maintenance-free lead acid battery.
External	Mains operation: 240V AC or universal input (110-240V AC) options.
Vehicle	12V DC supply adapter for vehicle operation, 2.1mm DC power socket on rear panel.
Battery Operation
Life	6-10 hours battery operation depending on the type of detector in use.
Status	Battery voltage is shown on display.
Environmental
Rating	IP 30
Temperature range	0ºC to +40ºC.
Physical Dimensions
Case	Strong metal case made of aluminium sheet with cast front bezel. Two front feet can be extended for easy viewing.
Size	H 100 mm (feet folded in), D 280 mm W 250 mm,
Weight	2.8 kg