Chapter 2: Analyzer Description
ABL77 Service Manual
Functional Description
Introduction
This section provides a general introduction to the analyzer.
Overview
The ABL77 Analyzer is an electromechanical instrument designed to measure
blood gas, pH, and electrolyte concentrations of whole blood.
The heart of the ABL77 analyzer is a 486 SX single board computer. It operates on
custom software in a Microsoft
®
Windows CE operating system. Peripherals
include a floppy disk, VGA color monitor with touch screen, thermal printer and a
custom board that performs all analog input and output functions.
An external AC to DC power supply provides system power. On board batteries
enable portable operation of the analyzer. An intelligent power control board
monitors system power and battery charge cycles.
After use, the analyzer may contain blood residue. Follow the
Long-Term Storage
Procedure
in
Chapter 8
to decontaminate the analyzer. Following
decontamination, the ABL77 analyzer should be disposed of in a safe and proper
manner.
Intended use
The ABL77 pH, blood gas and electrolyte analysis system is a portable, automated
analyzer that measures blood oxygen, carbon dioxide, pH, sodium, potassium,
chloride, ionized calcium and hematocrit in whole blood. The ABL77 system is
intended for use by trained technologists, nurses, physicians and therapists. It is
intended for use in a laboratory environment, near patient or point of care setting.
Measuring
principles
There are three different measuring principles employed.
•
Potentiometry: A potential is recorded using a voltmeter, which relates to the
concentration of the sample. A reference electrode is used to provide a stable,
fixed potential against which other potential differences can be measured. Used
for pH, CO
2
and electrolytes.
•
Amperometry: The magnitude of an electrical flow of current is proportional to
the concentration of the substance being oxidized or reduced at an electrode.
Used for O
2
.
•
Conductivity: The specific impedance of a sample as measured by two
conducting electrodes held at a constant voltage is directly proportional to the
conductive properties of the sample. Used for hematocrit and air-in-sample
detection.
Operating
conditions
The ABL77 system can be operated at an ambient temperature of 12-28 °C
(54-82 °F).
All calibration solution packs should be stored at temperatures between 12-28 °C
(54-82 °F). Do not freeze or expose to excessive heat or direct sunlight.
All sensor cassettes should be stored at temperatures between 5-32 °C (41-90 °F).
Do not freeze or expose to excessive heat or direct sunlight.
Altitude
conditions
The ABL77 system can be operated at altitudes from sea level to 1600 meters.
2-2
Rev.
F
