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Portable Tritium-in-Air-Monitor

Model: 7043


Tyne Engineering’s new handheld Tritium In-Air Monitor monitors for both tritium and gamma in a single robust, portable instrument.


  • Simple to use, with only one operating switch with four settings: Off, Sample, Pump, Set Up.

  • Gamma Compensation with four large ion chambers arranged in a cruciform configuration. Two chambers are used for measuring the air sample, and two are for compensation.

  • Less than 10% inaccuracy in 20 mR/hr field

  • High Sensitivity. The volume of a measured charge is 500 cc. The current amplification circuit employs ultra-low leakage technology. Each chamber has its individual amplifier, increasing the Signal-Noise Ratio of the analog circuit.

  • Sensitivity is 1µCi/m³.

  • Radon compensation is provided by the analog filter circuit designed to separate the radon spike. The software can distinguish the radon spike from the tritium signal occuring as a slow-change signal.

  • Ion-traps are built into each ion chamber.

  • Noble gas compensation is accomplished by interposing a desiccant cartridge between the ports of the measurement and compensation chambers. The airflow to and from these chambers is channeled through ports that are accessible from the instrument's faceplate. The noble gas signal can be displayed by the micro-processor.

  • Direct gamma measurement is provided using an installed GM tube.

  • Decontamination by purging of all 4 ion chambers can be achieved with use of the centrally installed cartridge heater.


Compensation for Gamma background is crucial in tritium measurement, since a gamma field of 1mR/Hr will generate 500 times the ionization generated in 1µCi/m³ of tritium. Tyne designed the four, 250 cc ion –chambers in a cruciform with each chamber connected to an ultra sensitive electrometer amplifier and filter. All signals pass through the ADC converter, and the micro-processor calculates and displays the tritium value. To cover high ranges of tritium a separate small ion chamber is used. Measurements such as flow from the solid-state flowmeter and chamber temperature are also monitored by the micro-processor.

Instrument output includes analog (0-5V, 4-20mA); relay alarm contact (30VDC, 1A) for operation of external equipment; and communication (RS232/RS485) to enable downloading or recording of information onto a computer. The TFT full color LCD display mounted on the surface plate clearly displays instrument readings in both digital and graphic format to show real time measurements and trends.

The well balanced, easy-to-carry instrument can be placed on its end for easy visibility of the touch screen monitors to operators working away from the instrument.

Batteries installed in the handle are easily replaced.

A powerful long-life pump can be used to draw air through a 10 meter tube. This allows the instrument to be used to measure the inside of rooms without the need to enter the room.


Sensitivity1µCi/m³ ( 0.05 DAC)
Accuracy±3µCi/m³ from 1 to 100µCi/m³, ±10% from 100µCi/m³ to 20,000 µCi/m³
Range1 µCi/m³ to 199,999 µCi/m³
Detector4 matched chambers - Two for measuring, two for compensation
Measuring chamber effective volume500 cc (2 measuring chambers of 250cc each)
Flow rate1.0 L/m
Zero stability±1µCi/m³ immediately after unit is powered on
Background cancellationLess than 10% of the reading change in 20 mR/hr field
Radon compensationIncluded in the software
Ion trapBuilt into each ion chamber
Dust filterBuilt into the unit.
Noble gas cancellationPorts for air inlet/outlet of measuring chambers and compensation chambers are accessible on surface plate so silica gel drier can be placed between the chambers to compensate for presence of noble gas.
Tritium DiscriminationInstrument can discriminate in a field of HTO and elemental H3 using the silica gel drier.
Purge/DecontaminationAll 4 Chambers can be heated up by a cartridge heater controlled by unit
DisplayGraphic touchscreen LCD display. Unit displays the values(tritium and Gamma) both in numerical format and graphical trend.
CommunicationCan be configured to RS232(Short distance) or RS485(Long distance).
Analog output0-5 V Linear or logarithmic voltage output.
Power supply2.5 V- 5V external power supply, or 3 C-cell battery. Total power consumption is 150mA.
Gamma measurementGamma is measured directly by the unit. Gamma measuring range is from 0.1mR/h to 10R/h
AlarmTritium alarms, gamma alarms, low air flow alarms will all be shown by red LED light and by an audible device.
Data loggingThe tritium and gamma values are logged every minute with current time and date stamp
Size and weight8"(L)x5"(H)x5"(W), 7 lbs.
DrierNote that the silica gel drier is not part of the standard equipment, but can be supplied as an extra.
Response Time30 seconds at 90% of signal