HF scientific MicroTUV Online UV %Transmission Sensor/Sampler (large) - Manual (Page 13)

Inside the Sensor module, warm dry air is constantly circulated around the exterior of the sampling cuvette
to prohibit condensation. A desiccant tray is provided to dry the heated air. To avoid flooding in case of cuvette
breakage within the sensor housing, a foot valve is included which normally seals the drain connection from
the outside air. This valve is a float valve, which only opens in the presence of water. In case of cuvette
breakage the float valve directs water to the outside of the Sensor/Sampler enclosure through an emergency
drain.
Controls for the Sensor/Sampler are Power On/Off, and the Pump On/Off. The CPU module contains L.E.D.
status lamps as shown below:
The Sensor/Sampler also contains a thermostatically controlled heater that is used for cold climates. The
heater’s fan runs constantly even though the heating elements are only activated at the set temperature. (50°F)
3.2 START UP
NOTE: 100% T solution can be purchased from HF scientific . If necessary, it can be purchased locally
(distilled water).
After the plumbing is complete the system needs to be bled of air. Turn the Sensor/Sampler power on. It may
take up to 8 minutes to purge the system of air. This will require that the CPU is reset, as it may shut off after
a few minutes of running air. Use the push button on the Power Supply Module to perform this.
Once the plumbing system is purged of all air and the flow head cleaned and locked in place, install the fresh
100%T solution container in the sampler inside the main cabinet.
4.0 CALIBRATION
The Sensor/Sampler requires calibrations occasionally to adjust for debris buildup on the cuvette. Calibra-
tions are initiated by periods set in the analyzer, usually every 24-48 hours. A calibration consists of a dark
reading and a 100%T reading. Dark readings set the low end of the readable scale and 100%T calibrations set
the upper end.
4.1 100%T CALIBRATION
TUV (04/03) Page 5
REV. 0.6
LED Name Purpose/Description
Lamp Heat Lamp Heater On (Blinking=Normal)
Pump Pump On
Lamp Lamp on (100 mS)
Valve Valve on during 100% Cal cycle
Flow Flow (On=NoFlow)
(Off=Normal Operation)
(Blinking=Low Flow)
During a 100%T calibration the solenoid/valve will switch the source of fluid supply from the effluent
sample, to the 100%T water. It will pump this water for a predetermined time and then shut the pump
down. During this shutdown period the Sensor/Sampler’s CPU will perform several calibrations and
will adjust its gain to the amount of signal available dependant on the condition of the optical path (debris
or contaminant on the cuvette walls). The solenoid/valve will then return to providing the sample to the
pump intake and the pump will restart. At this time the Sensor/Sampler is returned to normal on-line
operation.
WARNING: Using distilled water may affect accuracy of the TUV.