IAS-TP20 Portable Tritium-in-Air Monitor with Gamma Compensation
A 3.5 kg (7.7 lb) survey instrument that measures total airborne tritium (HT + HTO) in rooms, gloveboxes and shipping containers. A second ion-chamber pair subtracts external gamma, and a built-in GM tube reports the ambient dose rate at the same time.
Quick answer
IAS-TP20 is a portable survey monitor in the IAS-T tritium monitoring series from Iodine Air Systems. It measures tritium from 3.7 × 10⁴ to 3.7 × 10¹⁰ Bq/m³ (1 µCi/m³ to 1 Ci/m³). Battery / USB-C powered; calibration certificate and certificate of conformance included; price on quotation.
What the IAS-TP20 does
The IAS-TP20 is a portable tritium monitor for health physics technicians who need a real-time reading of tritium in air, not a lab result the next day. It carries four 250 mL ionization chambers. Two measure tritium in the sampled air. The other two are sealed from the sample and see only external gamma radiation, so their signal is subtracted. Each chamber has its own particle/ion trap, and each chamber pair has its own electrometer.
Air is drawn through the instrument at ≥ 1 L/min. With a sample tube attached, it can pull air from inside a glovebox, a transport container or a pipe penetration without the operator opening it. A built-in GM tube gives the ambient gamma dose rate from 1 µSv/h to 10 mSv/h (0.1 mrem/h to 1 rem/h), so one instrument answers both questions at a job site.
A heated purge clears the chambers after exposure to high concentrations (tritium "memory"). It is powered through the USB-C port.
Key features
- Gamma-compensated tritium measurement: 2 × 250 mL measuring chambers + 2 × 250 mL compensation chambers
- Built-in GM dose-rate channel: 1 µSv/h – 10 mSv/h (0.1 mrem/h – 1 rem/h)
- Optional wide range to 3.7 × 10¹³ Bq/m³ (1,000 Ci/m³) for high-inventory work
- Color touchscreen with live tritium and gamma values and a tritium trend graph
- Heated chamber purge to recover from high-concentration exposure
- RS-485 (RJ45) for remote data plus 2 relay outputs to drive beacons or interlocks
- USB-C for local data transfer, external 5–20 V power and data logging
- Runs on 3 C-size cells (lithium pack optional) or more than 20 hours on a USB-PD power bank
IAS-TP20 specifications
| Detectors | 2 × 250 mL tritium ionization chambers + 2 × 250 mL gamma-compensation chambers, each with particle/ion trap |
| Range (SI) | 3.7 × 10⁴ to 3.7 × 10¹⁰ Bq/m³ |
| Range (US units) | 1 µCi/m³ to 1 Ci/m³ (10⁻⁶ to 1 µCi/mL) |
| Range as HTO DAC multiples | 0.05 DAC to 50,000 DAC (HTO DAC 2E-5 µCi/mL) |
| Optional wide range | 3.7 × 10⁴ to 3.7 × 10¹³ Bq/m³ (1 µCi/m³ to 1,000 Ci/m³) |
| Sensitivity | 4 × 10⁴ Bq/m³ (≈ 1.1 µCi/m³) |
| Gamma dose-rate channel | GM tube, 1 µSv/h – 10 mSv/h (0.1 mrem/h – 1 rem/h) |
| Stability | < ±2% over 24 h; < ±5% over 30 days |
| Response time | 30 s to 90% of final signal |
| Sample flow | ≥ 1 L/min (≥ 0.035 cfm) |
| Display | Color LCD touchscreen: tritium and gamma values, tritium trend |
| Power | 3 × C-size cells (lithium optional); 5–20 V DC via USB-C; optional USB-PD power bank > 20 h |
| Communication | RS-485 via RJ45 (remote); USB-C (local), on-board data storage |
| Alarm outputs | Local audible and visual alarm; 2 relay outputs |
| Operating environment | −10 to 40 °C (14 to 104 °F); 0–95% RH at 35 °C, non-condensing |
| Dimensions (with handle) | ≤ 285 × 218 × 135 mm (11.2 × 8.6 × 5.3 in) |
| Weight | ≤ 3.5 kg (7.7 lb) |
Specifications are nominal manufacturer values and may change. Confirmed values are stated on the quotation and data sheet. DAC multiples use the tritiated-water DAC of 2 × 10⁻⁵ µCi/mL (7.4 × 10⁵ Bq/m³) from 10 CFR 20 Appendix B and 10 CFR 835 Appendix A.
Typical applications
- Routine air surveys in tritium laboratories and fuel-cycle rooms
- Checking glovebox or enclosure atmospheres before a bag-out or opening
- Screening tritium shipping packages and transport containers
- Leak searches along tritium process lines
- Fusion facility commissioning and maintenance entries
- Tritium light-source and self-luminous sign production areas
- Emergency response and incident characterization
US supply, documentation and quality
Iodine Air Systems supplies the IAS-T series as an authorized distributor. Instruments are built by our manufacturing partner to our US configuration. Each quotation states the exact deliverables, lead time and country of origin.
- US power version: 120 V AC / 60 Hz for mains-powered models (export versions for 220–230 V / 50 Hz).
- Factory calibration certificate with every instrument, stating the calibration method and reference standards.
- Certificate of conformance and product certification documents supplied with the quotation.
- Specifications in SI and US units, with ranges stated in µCi/mL and in multiples of the tritium DAC (10 CFR 20 Appendix B / 10 CFR 835 Appendix A), so they drop straight into your procedures.
- Commercial-grade supply. Instruments are supplied as commercial-grade items, not as 10 CFR 50 Appendix B / NQA-1 safety-related items. For safety-related use, we support the purchaser's commercial-grade dedication with critical-characteristic data and test records.
- Price on quotation. Price depends on model, options, quantity, documentation package and destination.
Compare with related IAS-T models
Rack-Mount Area Tritium Air Monitor
Fixed area monitor (19-inch rack)
View IAS-TA20 →IAS-TW10Tritium Surface Contamination (Wipe) Monitor
Surface contamination / wipe monitor
View IAS-TW10 →IAS-TG30Glovebox & Process Tritium Monitor
Process monitor (sealed, all-metal)
View IAS-TG30 →See the full IAS-T tritium monitor range or use the tritium DAC converter to check a reading against your limits.
IAS-TP20 FAQ
Can the IAS-TP20 measure tritium inside a glovebox without opening it?
Yes. Connect a sample tube to the inlet and the instrument draws the box atmosphere at 1 L/min or more through its measuring chambers. Tell us the glovebox gas (air, nitrogen, argon or helium), because ion-chamber response depends on the carrier gas.
What does gamma compensation do on a portable tritium monitor?
Ion chambers also respond to external gamma radiation. The IAS-TP20 has a second chamber pair that sees only external gamma, and the instrument subtracts that signal, so a gamma field does not show up as a false tritium reading.
What batteries does the IAS-TP20 use?
Three C-size cells, with a lithium pack as an option. It also runs from 5–20 V DC through USB-C, and an optional USB-PD power bank gives more than 20 hours of operation and powers the heated chamber purge.
Is the IAS-TP20 sensitive enough for DAC-level work?
Its lower range limit is 3.7 × 10⁴ Bq/m³ (1 µCi/m³), which is 0.05 of the occupational DAC for tritiated water (2 × 10⁻⁵ µCi/mL = 7.4 × 10⁵ Bq/m³). It reads well below a 1 DAC alarm point. For environmental-level measurements, use bubbler or desiccant sampling with liquid scintillation counting.
How much does the IAS-TP20 cost?
The IAS-TP20 is priced on quotation. The price depends on options, quantity, power version, documentation package and delivery destination. Send the quote form on this page or email sales@iodineairsystems.com, and we reply with price, lead time and the list of documents supplied.
Is the IAS-TP20 available for US 120 V power?
Yes. Mains-powered IAS-T models are available in a 120 V AC / 60 Hz US version, and in 220–230 V / 50 Hz for export. The IAS-TP20 itself runs on batteries or 5–20 V DC via USB-C.
What documents come with the IAS-TP20?
A factory calibration certificate, a certificate of conformance, product certification documents and an English operating manual. A commercial-grade dedication support package is available for purchasers who dedicate the instrument for safety-related use.
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