Page
6
4.0. CONFIGURATION
4.1. EXTERNAL
FEATURES
The front panel features include:
1. the digital panel meter, 1 to 19,999
μ
Sv/hr
2.
function
control
knob
3. alarm level control knob, 2 to 1,000
μ
Sv/hr
4. red LED; dual function; low battery, indicates when the D-cell batteries need to be
replaced and indicates red if the high voltage power supply (HVPS) has a malfunction
5. signal level alarm LED
6. low flow alarm LED
7. acoustic
signaler
8. mute push-button
9. calibration potentiometer (under phillips head screw)
10. offset potentiometer (small knob)
11. six sample hose barbs
12. two D-cell battery compartments
Side features include:
13. jack for external charger, 3 to 3.3Vdc, 1.2A-3A,
DO NOT SUBSTITUTE, use only the
recommended power supply
14. 8-pin mini-din receptacle for RS232
15. GAMMA CHECK label for position of check source, refer to section 6.0.
16. snap holder for dust filter
4.2. HOSE
CONNECTIONS
The instrument may be operated in either of two modes. In the first mode, the instrument will
respond to any radioactive gas passing through the instrument as well as tritium. In the second
mode, it will respond only to HTO, even in the presence of other radioactive gases. The external
plumbing (hose attachments) is selected to suit the mode in use.
FIRST MODE (refer to Figure 2) Measures total tritium plus any noble gases when present
A sniffer hose is attached to a small in line dust filter, which is directly attached to the “IN” hose
barb. The other measurement chamber hose barb is routed to the inlet of the pump by means of
a short piece of hose. Connecting a short loop of hose to each hose barb closes off the
compensation chambers hose connections.
SECOND MODE (refer to Figure 2) Measures HTO only with noble gas compensation
In this mode, the exhaust from the measurement chambers is connected to a desiccant cartridge.
The exhaust end of the desiccant cartridge is connected to a second dust filter and then to the inlet
of the compensation chamber. The other compensation chamber hose barb is routed to the inlet
of the pump by means of a short piece of hose. In this mode, the sample stream passes first through
the measuring (upstream) chambers, and then through the desiccant cartridge, it continues through
the compensation (downstream) chambers and finally exits via the pump.
Note 1: Never Operate The Instrument Without A Dust Filter In The Sample Stream
Note 2: The Instrument Must Be In Thermal Equilibrium With Its Surroundings.
Note 3: To Avoid Erratic Response, The Pump Must Always Be Placed Downstream Of
The Last Ionization Chamber In The Sample Path.