When a gamma ray enters into the NaI crystal, the photo multiplier outputs a pulse with amplitude proportional to gamma ray energy absorbed by NaI crystal. It adopts spectrum stabilization technology to set up windows with different energies. The counting rate of each energy window is sent to the surface system by electronic circuits. After processed by surface system, Th, U and K contents are calculated out.

It owns independent IP address and communicates with telemetry / GR tool by Ethernet, which can receive the command, and send digital signal to telemetry /GR tool. It can offer the total amount of natural gamma ray and amount of Th, U and K. This data is sent to surface system with 256 channels full spectrum technology. 

It is composed of electronic cartridge, sonde and housing with material of precipitation hardening stainless steel.

Working Temp.:                        -25 -175℃

Max. Pressure:                          140MPa

Storage Temp. :                       -40-70℃

Shock:                                      50g  3D(11ms)

Vibration:                                   5g  3D(10~60Hz)

Power Supply:                             250VAC, 50Hz

Measuring Range:                          0~500API

Resolution:                                 <12%（20℃）

                                                <15%（150℃）

Logging speed:                             450m/h

Measuring Accuracy  :

Th          ±1.5PPm

U          ±1.5PPm

K            0.1%

Vertical Resolution:                   500mm

Investigation Depth:                 300mm

O.D:                                       99mm

Length:                                   1900mm

Weight:                                    80kg