RKI Instruments GD-K11D - Manual (Page 9)

Model GD-K11D Operator’s Manual Description • 5
Detection System
The Model GD-K11D’s detection system consists of the sensor, lithium battery, amplifier,
and display board (see Figure 1.)
Sensor
Through a series of electrical and chemical reactions, the sensor produces an electrical
current that is proportional to the detection range of the target gas.
Electrodes within the sensor housing are surrounded by liquid electrolyte. The electrical
and chemical reactions are facilitated by the electrolyte.
Battery
The 3.6-volt lithium battery maintains the bias voltage on the sensor when the
Model GD-K11D is not receiving incoming power.
Amplifier
The amplifier is the circuit board to which the display board is mounted. The power
switch, fuses, and terminal strip are also mounted to the amplifier circuit board.
The amplifier converts the output of the sensor to a 4 to 20 mA signal (that is proportional
to the detection range of the Model GD-K11D) and converts the signal to a digital reading
on the display screen.
CAUTION: The potentiometers on the amplifier circuit board are factory-set. Do not adjust them.
Display board
The display board includes the display screen, status lights, program buttons, and
adjustment potentiometers. The display board is mounted to the amplifier by standoffs.
NOTE: The display screen and status lights are visible through a window in the housing
cover.
Display screen
The display screen displays the current gas reading of the Model GD-K11D’s target gas.
The display screen also displays operational and error messages.