Carbon Monoxide Alarm User Manual

Page 9
1.1.8 Classification for intrinsic safety
The PhD
2
is Classified by Underwriters Laboratories, Inc.
and the Canadian Standards Association as to Intrinsic
Safety for use in Hazardous Locations Class I, Groups A,
B, C, & D. This means that the PhD
2
has been
successfully tested for safety in combustible gas / air (21
% oxygen) mixtures.
1.1.9 Options
1.1.9.1 Sensors
The PhD
2
may be configured as a one, two, three, or four
sensor design. The PhD
2
measures oxygen, combustible
gas, and up to two additional toxic gases.
The sensor configuration may be changed or added to in
the field, or specified at the time of purchase.
1.1.9.2 Batteries
Two types of rechargeable batteries are available for use
in the PhD
2
design. The type of battery selected must be
specified at the time of purchase.
NiCad
A removable NiCad battery pack is available as an option
with the PhD
2
design. The NiCad battery pack is secured
by two screws located on the bottom of the PhD
2
case,
and may be removed or replaced without disassembly of
the instrument.
Sealed lead-acid:
The PhD
2
may also be equipped with an internally
housed, sealed lead-acid rechargeable battery. Removal
or replacement of the sealed lead-acid battery requires
disassembly of the instrument case.
Chapter 2 of the PhD
2
owner's manual covers battery
replacement and charging procedures.
1.1.9.3 Battery powered sample draw pump
An optional slip-on, motorized sample-draw pump is
available for situations requiring continuous "hands free"
remote monitoring. The rechargeable, UL Classified,
battery operated pump contains a unique pressure sensor
which detects water or other fluids being sucked into the
unit, and immediately acts to shut off the pump in order
to protect the PhD
2
sensors, pump, and other
components. The pump design includes a loud audible
alarm and bright red LED alarm light to additionally
indicate a low flow condition.
The battery-operated pump has its own rechargeable
power supply. On a full charge the pump should run
continuously for at least eight hours.
1.1.9.4 Computer Link Kit
A PhD
2
Computer Link Kit and Gas Detection Database
program is also available. This program allows you to
store information on a PC and retrieve it for further
analysis.
1.2 PhD
2
design components
(1) Case: The instrument is enclosed in a solid, stainless
steel impregnated polycarbonate case. A water resistant
PVC gasket between the upper and lower sections of the
case protects against leakage or exposure to liquids.
(2) Front face: The front face of the instrument houses
the meter display, alarm lights, and photo-sensor.
(3) LCD display: A "Supertwist" liquid crystal display
(LCD) meter allows display of readings, messages, and
other information.
(4) Alarm lights: Four LED (light emitting diode) alarm
lights provide a visual indication of alarm state. Each
light is dedicated to a single gas, and emits a bright red
light when a sensor alarm level is exceeded.
(5) Photo-sensor: A photo-sensor is used to monitor
the level of background illumination. A back-light
automatically brightens the meter display whenever the
instrument is taken into a dark area.
(6) On / Off MODE button: The large black push-button
is called the MODE button. It is used to turn the PhD
2
on
and off, as well as to control most of the operations of the
instrument.
(7) Key pad cover: The key pad cover protects the four
mini push-buttons on the instrument key pad.
(8) Sensor compartment cover: The sensors are
protected by a vented sensor compartment cover. A
water resistant PVC gasket and inner-liner protect the
sensors against leakage or exposure to liquids. (A
special sensor cover which does not include an inner-liner
is used whenever “corrosive gas” toxic sensors are
installed.) The solid cover also provides increased
sensor position stability.
(9) Audible alarm orifice: A cylindrical orifice extending
through the top of the case houses the loud (100 dBA at
six inches) audible alarm. A water resistant Porex

filter
protects against leakage or exposure to liquids.
(10) Battery charger / RS232 connector: A water
resistant connector on the upper left hand side of the
case functions both as the battery charger and RS232
computer interface port.
(11) Bottom surface: A sturdy clip allows the user to
wear the PhD
2
on a belt or other article of clothing. A
removable NiCad battery pack is available as an option.
If this option has been selected, instead of a belt clip, the
battery pack is secured into the case by two screws
located on the bottom of the PhD
2
.
(12) Key pad: The key pad consists of, four mini push-
buttons, "Cal," "Alarm," "+," and "-". These buttons are
used for fresh air (zero) adjustment, calibration, and
programming procedures. (Use of these push-buttons
is reserved for authorized personnel.) Chapter 2 of
the PhD
2
owner's manual covers battery replacement
and charging procedures.