Chemtrac HydroAct 4, Руководство пользователя

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36 Chapter 3. Sensors
The PC6 Particle Counter is equipped with a class 3R laser and should not be tampered
with in any way.
In order to provide maximum user safety the PC6 Particle Counter particle counter was designed
with the following issues in mind.
• All circuitry is enclosed with a protective non-conductive housing.
• No user serviceable parts.
• No user replaceable parts.
• No access to laser.
Please ensure that the user reads the manual before starting installation.
• Do not attempt to disassemble the unit.
• Keep enclosure sealed tight, water must not be allowed to enter the housing of the unit.
• Use a mild non-abrasive cleanser when cleaning the unit.
• Do not drop or jar the unit.
• Do not modify any internal electrical wiring or electronics.
Risk of electric shock. Connect only to suitable isolated, hard wired electrical outlet. It is
recommended that the outlet is protected by an RCD (Residual Current Detector) or is in
any event in compliance with all local electrical regulations. Do NOT bury electrical supply
cable.
3.1.1.2 Environmental Considerations
The sensor contains electronics, sapphire, aluminum, delrin, kynar and polycarbonate. Inside the
sensor there are electronics. Please use this product in a manner sensitive to the environment and
at the end of its life dispose or recycle in a manner appropriate at that time in compliance with local
regulations.
3.1.2 Theory of Operation
The PC6 Particle Counter is designed to count particles 2 to 750 µ m in diameter and size (i.e. sort
by size) particles ranging from 2 to 127 µ m in diameter. Particles larger than 127 µ m will be sized as
>127 µ m particles. Particles are divided into size ranges and the number of particles counted in each
of these ranges is reported as counts per milliliter, counts per 100 milliliters, raw counts, or PPB.
The PC6 Particle Counter consists of an optical sensor and counting electronics. The sensor
consists of a 780 nm infrared laser diode, a light detector, and two sapphire windows. The detector
converts light energy into electrical voltage. The laser light is directed through both windows and onto
the detector. Sample flow passes between the windows, so that any particles in the sample will pass
through the laser beam. Each particle will block a small percentage of the light that hits the detector,
changing the electrical output of the detector. Since the particles are moving rapidly, each particle will
produce a short electrical pulse at the output of the detector. The amplitude of the pulse correlates
to the size of the particle. The output of the sensor is a stream of pulses of varying amplitude, each
corresponding to a particle. This type of device is known as a light blocking or light extinction sensor,
see the following diagram.