Nuclear power plant tritium monitor model 421 NPPM

Produced by Overhoff Technology Corporation

This tritium monitor is a version of the OTC standard 321/421 series, configured for the special environmental conditions associated with nuclear power plants, especially those of the CANDU type. This monitor can be used for other applications where tritium specific measurements in the presence of other radionuclides are required.

Nuclear power plant tritium monitor model 421 NPPM (.pdf)

Technical specifications

Range, typical

two, automatically switch
0.1 – 10,000 μCi/m3 low range
1.00 – 200.00 mCi/m3 high range
other ranges available

DISPLAY

4½ digit DPM

ACCURACY

±2 % of reading, ± L.S.D., whichever is greater

STABILITY AND DRIFT

±1.0 μCi/m3long term (thirty days), ambient temperature conditions

 

NOISE

± 1.5 MBq/m3, 1 sigma with alpha suppression in use

RESPONSE RATE

three linear electronic time constants
approximately 40 seconds for signals up to about 80 μCi/m3
approximately 10 seconds for signals from 80 to 10,000 μCi/m3
approximately 3 seconds for signals above 1.00 mCi/m3

WARM UP TIME

less than 10 minutes

VOLUME

measuring: 1,200 cm3
total wetted: 2,000 cm3

TEMPERATURE

storage: -40°C to +65°C
operating: +0°C to +55°C

HUMIDITY

0 to 95 % R.H. (non-condensing)

VOLTAGE

230 VAC +10 %, 50 Hz, 20 W max