Tritium Monitors: Portable, Area, Glovebox, HT/HTO and Wipe

What is a tritium monitor?

A tritium monitor measures the radioactive hydrogen isotope tritium (H-3), usually in air or process gas, and reports the concentration in real time, typically in Bq/m³ or µCi/m³. Most real-time tritium monitors draw sample gas through an ionization chamber, because tritium betas are too weak to penetrate a detector window.

Why can't a Geiger counter detect tritium?

Tritium emits beta particles with a maximum energy of 18.6 keV and an average of about 5.7 keV. They travel only a few millimeters in air and cannot pass through a Geiger-Müller tube window, so the tritium itself has to be brought inside the detector volume: sample air through an ion chamber, or a wipe counted in a wipe monitor or by liquid scintillation.

Which IAS-T tritium monitor do I need?

Use the IAS-TP20 for portable surveys, the IAS-TA20 (gamma-compensated, rack) or IAS-TA30 (cabinet) for fixed room monitoring, the IAS-TG30 or IAS-TG10 for gloveboxes and process gas, the IAS-TS40 when HT and HTO must be measured separately, the IAS-TW10 for surface wipes, and the IAS-TD20 module for integration into your own system.

What is gamma compensation in a tritium monitor?

Ionization chambers respond to external gamma radiation as well as to tritium in the sample. A gamma-compensated monitor has a second chamber that sees only the external gamma field, and its signal is subtracted. The IAS-TP20 and IAS-TA20 are gamma-compensated.

What is the difference between HT and HTO?

HT is elemental tritium gas; HTO is tritiated water vapor. HTO is far more readily taken up by the body. Under 10 CFR 835, the DOE DAC for HTO is 2 × 10⁻⁵ µCi/mL and for elemental tritium 2 × 10⁻¹ µCi/mL, a factor of 10,000. The IAS-TS40 measures the two forms separately.

What is the DAC for tritium, and how do IAS-T ranges compare?

The occupational DAC for tritiated water is 2 × 10⁻⁵ µCi/mL (7.4 × 10⁵ Bq/m³) in 10 CFR 20 Appendix B and 10 CFR 835 Appendix A. IAS-T air monitors start at 3.7 × 10⁴ Bq/m³, which is 0.05 DAC, so they read well below a 1 DAC alarm point and up to hundreds of thousands of DAC.

Are IAS-T tritium monitors available for 120 V / 60 Hz?

Yes. Mains-powered IAS-T models are supplied in a 120 V AC / 60 Hz US version, and in 220–230 V / 50 Hz for export.

Can IAS-T monitors be used in safety-related applications at NRC-licensed plants?

IAS-T monitors are supplied as commercial-grade items, not as 10 CFR 50 Appendix B / NQA-1 safety-related items. A licensee may dedicate them for safety-related use under its own commercial-grade dedication program, and we supply critical-characteristic data and test records to support that.

How are IAS-T tritium monitors calibrated?

Each instrument ships with a factory calibration certificate that states the calibration method and reference standards. Recalibration arrangements are included in the quotation.

How much does a tritium monitor cost?

IAS-T monitors are priced on quotation. The price depends on model, options, quantity, power version, documentation and destination. Use the quote builder on this page, email sales@iodineairsystems.com or call +1 (307) 533-0268.

Where are IAS-T tritium monitors made?

Iodine Air Systems supplies the IAS-T series as an authorized distributor. The country of origin is stated on every quotation and on the instrument marking, as US import rules require.

Do you ship tritium monitors outside the United States?

Yes. We quote worldwide, with 220–230 V / 50 Hz versions for export markets. Heavy-water reactor operators and fusion projects outside the US are among the intended users.