ASM-990 Series Advanced Survey Meter

The ASM-990 Series Advanced Survey Meter can detect alpha, beta, gamma, or x-ray radiation within an operating range of 1 μR/hr to 1 R/hr (1 to 5,000,000 CPM), depending on the selected probe (Geiger-Mueller, neutron, proportional counter, scintillation). With the proper probe combination, this meter can be used as a general survey meter, an area monitor, a wipe-test counter, and a contamination monitor.

Designed to meet the high-technology require- ments of health physics, medical physics, and nondestructive testing applications, the ASM-990 Series is well-suited for a wide range of end users, including: Radiation safety officers, nuclear medi- cine laboratories, diagnostic x-ray and hospital emergency-room technicians, environmental-health physicists, and emergency responders.

The unit, with purchased probe, is shipped calibrated and ready-to-use and includes an MHV connector to ensure compatibility with all Fluke Biomedical probes. The 992 includes a fully cali- brated internal energy-compensated 1 R/hr GM detector. The 993 features a fully calibrated internal pancake detector, as well as an internal energy- compensated 1 R/hr GM detector.

Data logging modes

The ASM-990 Series´ Log Data feature can easily be accessed via the setup sub- menu. The unit can log/save a maximum of 500 data points in any of three sepa- rate modes (manual and survey modes can utilize the optional barcode scanner).

Manual: Individual rate data points can be saved by pressing the Start/Stop/Rst/ Save button.

Timed: A data point will automatically be saved at user-selectable time intervals in the range of 1 second to 255 seconds.

Survey: Programmed sequences can be accessed via the menu system. Pressing the Start/Stop/Rst/Save button saves the current reading and displays the next survey location.

Programming of survey sequences, as well as retrieval of logged data, is accomplished via the built-in IrDA port.

Label names up to 20 characters can be programmed into the unit to identify the individual survey locations.

Probe connector: The unit is available with an MHV connector. The unit can be used with multiple probes (5 total) by selecting the appropriate probe from the main menu. All calibration data for each probe is stored in the unit´s EEPROM.

Specifications

ASM-990 and ASM-992

Operating modes: Rate, timed-peak hold, integrate, data logging, and scaler (dual option: “based on measurement” or “based on time”)

Operating rate ranges (dependent on selected probe): Complementary units in the integrate mode with the integrated time value in seconds

μR/hr	mR/hr	R/hr
μrem/hr	mrem/hr	rem/hr
μSv/hr	mSv/hr	Sv/hr
CPM	CPS
DPM 99mTc	DPS 131I
Bq ¹²⁵I	kBq¹²³I	MBq ²⁰¹Tl
μCi ⁶⁷Ga	mCi ¹⁸F	Ci ⁵⁷Co
μR	mR	R
μrem	mrem	rem
μSv	mSv	Sv
C (counts)	kC	MC
D (distintigrations)	kD 99mTc	MC 131I

Accuracy (dependent on selected probe): Within 10 % of reading between 10 % to 100 % of full scale indication on any range, exclusive of typical energy dependence

Detector: Accepts GM detectors and scintillation probes operating at high voltages between 500 volts and 1300 volts

Temperature range: -10 °C to 50 °C (14 °F to 122 °F)

Relative humidity: 0 % to 95 %, non-condensing

Warm up time: 5 second diagnostic check

Check source: Natural uranium, mounted on the case

Power requirements: Two “D” cells, 150 hours operation, automatically indicates when battery is low

Housing material: Proprietary polycarbonate, splash-proof case

Display: Liquid crystal display, 5.6 cm x 5.6 cm (2.2 in x 2.2 in)

Dimensions (LxWxH): 10.5 cm x 27.7 cm x 6.4 cm (4.1 in x 10.9 in x 2.5 in)

Weight (without probe): 0.95 kg (2.1 lb)

ASM-992 and ASM-993

Range: 0.1 mR/hr to 1 R/hr

Radiation detected: Gamma above 60 keV

Accuracy: ± 10 % of reading between 10 % and 100 % of full scale on any range, exclusive of energy dependence

ASM-993

Range: Background to 80 mR/hr

Radiation detected: Alpha above 3.5 MeV, beta above 35 keV and gamma above 6 keV

Window: 15 cm² (1.75 in ∅) mica, 1.4 mg/cm² to 2.0 mg/cm² Typical background: 30 CPM

Protective screen: Stainless steel, hex- agonal pattern providing 86 % open area

Accuracy: ± 10 % of reading between 10 % and 100 % of full scale on any range, exclusive of energy dependence (protective cover open)

Effeciency: The internal pancake detector efficiency is shown below. In a recent performance check, the numbers shown represent typical results obtained:

Isotope % Efficiency
¹⁴C ²⁴¹Am 5% 8%
⁹⁹Tc ¹²⁹I 12 % 2%
¹³⁷Cs ²³⁰Th 24 % 15 %
⁹⁰Sr ²³⁹Pu 59 % 12 %
³⁶Cl 26 %

Note: The efficiency formula used to calculate the % Efficiency is: Eff. % = (CPM x 100)/DPM

Isotope	% Efficiency
¹⁴C	²⁴¹Am	5%	8%
⁹⁹Tc	¹²⁹I	12 %	2%
¹³⁷Cs	²³⁰Th	24 %	15 %
⁹⁰Sr	²³⁹Pu	59 %	12 %
³⁶Cl		26 %

Dimensions (LxWxH): 10.5 cm x 27.7 cm x 6.4 cm (4.1 in x 10.9 in x 2.5 in)

Weight (without probe): 1.09 kg (2.4 lb)

Typical energy dependence

Internal energy compensated 1 R GM detector

ASM-990 Series

Advanced Survey Meter