VIASYS Vmax Encore, Техническое справочное руководство

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Technical Reference Manual
Vmax Encore
L2707
1–13
Chapter 1 Introduction
MIXING CHAMBER/BLOWER
A 2.6-liter mixing chamber is located in the Pneumatics/Fan Assembly. This chamber is used for
mixing expired gas during exercise and calorimetry testing. The chamber also houses the variable
volume, high capacity blower used for dilution testing. The blower volume is controlled by the
computer and is continuously variable from 12–60 LPM.
The blower’s on/off switch is located on the front of the Pneumatics/Fan Assembly. Safety circuitry
will automatically turn the blower up to full volume if communication with the computer is lost for
any reason.
A battery-powered alarm will sound if the blower’s on/off switch is in the on position and there is a
power loss to the Analyzer Assembly.
DEMAND REGULATOR
A high-capacity Demand Regulator is located in the Pneumatics Assembly. This regulator is used
to deliver test gases (oxygen or diffusion mixture) to the patient on inspiratory demand during the
FRC, SBO
2
, P100, intra-breath, compliance, and DLCO tests. The delivered flow range is 0–6 LPS.
PERMA PURE
®
NAFION
®
DRYING TUBE
The calibration gas and the patient's exhaled gas pass through a Perma Pure drying tube before
entering the gas analyzers. The absorption and evaporation properties of the Nafion material in the
drying tube ensure that the relative humidity in the exhaled gas and in the calibration gas is
equilibrated to ambient conditions (room air) when they are sampled in the analyzer. This results in
a high degree of accuracy in the actual gas concentration measurements and removes the need for
external drying crystals. The tube is wrapped in protective braiding to prevent pinching and
crimping.
SOLENOID AND DEMAND VALVE CONTROL
All flushing, sealing, and gas flow control is provided by an integrated system of solenoid valves,
one-way valves, and a high-capacity demand valve. The computer controls these valves
automatically. The computer program is designed to take the operator through the appropriate
steps of any given test, thereby insuring that all valves are in the correct position at all times. The
internal pneumatic connections are of rigid construction and are tested at elevated pressures to
insure excellent, long-term seals.
TEMPERATURE SENSOR
A temperature sensor is located inside the air circulation inlet port on the Analyzer Assembly to
measure ambient room temperature. This makes operator-entry of the room temperature from a
separate room thermometer unnecessary.