The Reader II consists of 2 units, the instrument box which is the operational and
calculating unit and the reader pen, which is the measurement unit.

Main components of the instrument box are the microprocessor, the LCD display and
push buttons for operation. The elements of the Reader Pen are the Light Emitting
Diodes (LEDS), a photodiode, a light dark detector and the functional design. A pen
cable connects these two units together. The pen holder is located to the right of the
display on the instrument box. The pen is placed in the holder to protect it when not
in use. In front of this holder, there is a lid and on the rear side of the lid a white
calibration device is placed


The reader pen contains 3 pairs of LED’s - Red, Green and Blue. Reflected light from
the test sample is measured, relative to a white sample, a light sensitive photodiode
circuit. When a specific test from the menu is chosen, the required LED’s illuminate
the sample to be measured. The sample will reflect some of the light and give rise to
a constant current in the photodiode, which will discharge a capacitor linearly from
the voltage V1 to a lower voltage V2. When V2 is reached a signal is given to the
micro processor. The micro processor measures the time (T), it takes to change the
voltage from V1 to V2. The intensity of reflected light (l) is then inversely proportional
to T and the microprocessor converts the time to a concentration value, which will
then be displayed. When the pen is placed over the sample and the pen sleeve is
push down, light or dark detector registers that the environment has changed from
light to dark and the measurement is automatically started. The sleeve will ensure
that the pen is held stable in a vertical position and that external light is excluded
from the sample.

White calibration adjusts for any differences in measuring conditions and variation of
pen tips. The white calibration device, which is stored under the lid, protected from
light and dust. The reader should be calibrated prior to each series of measurements
and prior to each single measurement.


Hb A1 C
Micro Albumin
C Reactive Protien
Pharmacy & Diagnostic Clinics
Biochemistry Division
Tel: +917034707700        Email: