Equipment in use

Shinjuku Yoyogi Citizen Monitoring Station use two different instruments in accordance with your request.

If you would like more precise measurement results, we use ‘germanium semiconductor detector’. (the first model modified GCD-60200, the second model GCD-70200)
If you would like to monitor many specimen materials with moderate detection limits, we use ‘NaI (TI) scintillation detector’.

Germanium semiconductor detectors made by Baltic Scientific Instruments, Ltd. (the first model modified GCD-60200, the second model GCD-70200)

Model-GCD60200
Model-GCD70200

They can measure a small amount of radioactivities, so they can perform very precise radioactivities (gamma ray) measurements of food and various environment samples. They are suitable for those who want to monitor in exact detail. They have the characteristics of avoiding false positives of natural radioactive materials.

Detectable type of nucleus
Cs (cesium) -134, Cs (cesium) -137, I (iodine) -131, K (potassium) -40

Detectable volume
2l, 1l, 500ml, 200ml, 70ml
(We select the most suitable volume for specimen materials.)

Measurement time
You can choose from three types: 1 hour, 4 hours, 16 hours.

Rough standard of detection limits
Measurement time (hour) Detection limits (Bq/kg)

Scintillation detector mede by Gammadata Instrument (GDM-20)

This is a type of detector which can provide the most precise results next to germanium semiconductor detectors.
They are so reliable that many public offices, local governments, research bodies and food related companies adopt them.
We recommend it to those who want to monitor inexpensively with moderate accuracy.

Model-GDM-20

Detectable types of nucleus
Cs (cesium) -134, Cs (cesium) -137, I (iodine) -131, K (potassium) -40

Detectable volume
1l, 500cc, 200cc
(We select the most suitable volume for specimen food)

Measurement time
Rough standard of detection limits
Measurement time (hour) Detection limits (Bq/kg)

Etc.
Our monitoring station has been technologically supervised by Mr. Yoshinobu Koizumi, a former member of Isotope Science Center, The University of Tokyo.