The 350 series calorimeters determines the tritium mass in grams (g) and activity in units

of Curies (Ci) or Becquerels (Bq) by measuring the total heat output resulting from the

radioactive decay of tritium. The design has application to a wide range of measurement

requirements. These include in-plant accountancy measurements, shipper - receiver dif-

ference measurements, the identification of empty transport containers and international

safeguards measurements. The instrument also has a role in replacing a proportion of

measurements performed using the PVTc technique as the calorimetry measurement

process is non-intrusive.

The instrument is designed to measure tritium with a mass or activity ranging from over

10 g or 100 kCi (3.7 x 1015 Bq) down to less than 10 mg or 100 Ci (3.7 TBq). Measure-

ment uncertainty ranges from better than 0.2 % at 50 kCi to between 5 % and 10 % be-

low 1 kCi. Measurement times range from less than 2 hours to 4 - 5 hours depending on

the temperature of the getter and the quantity of tritium being measured.

The calorimetry measurement method is independent of sample pressure, chemical com-

position and the presence of any other non-radioactive material, for example hydrogen,

deuterium and helium. The measurement procedure is automated and requires almost no

manual intervention, with the exception of loading and unloading the calorimeter. A

calorimetric measurement of the tritium decay heat provides a direct measure of the total

tritium activity or tritium mass based on precise electrical power measurement.

User friendly software is included that operates under NT4 or Windows 2000 and is fully

network compatible. Both end point power and equilibrium fitting software routines are

included in the standard package, as are decay correction for both tritium and plutonium.

Measurement data is archived and can be analysed off line at any time.

Variations to the standard design for different requirements and for special sample types

or sample packaging can be accommodated.

Thermal power measurement accuracy ·

Two versions are available. Unit can

·

better than 1.0% over the operating

be mounted on a single trolley or the

range and better that 0.2% at 1.0

control console and thermal element

Watts power.

can be separated by up to 5 meters

Custom design parameters means vari- ·

Weight of trolley mounted version is

·

able measurement chambers can be

Power consumption 1000 watts maxi-

·

Measurement range from 5mW to 20

mum 110/230VAC

·

Watts. The minimum power sensitivity

5mW with 100% RSD