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3
Photometer 7500
1 Mode or Test Identification.
2 Dialogue screen - prompts and choices will be
displayed as a list. Select using up/down arrows.
3 Info Panel - displays status icons, date/time
and Sample/Operator ID
4 Action select - choices are displayed as a row.
Use left/right arrows to select.
Info Panel Icons
Icons
Description
Battery status
Upper/lower case text/number entry
Hotkey Entry Mode Enabled
USB connected
Hard Drive/COM port mode
3.2 Taking a Sample
The first critical step in any analysis is taking a
representative sample. When selecting a sample point
a number of care points are recommended as follows:
• Ensure the sample point is safe to access and
follow all relevant/required precautions
• When sampling from a tap or outlet, remove
any attachment and clean the tap/outlet with
a dry cloth before allowing the tap/outlet to
run for 1 minute prior to sample collection
• When sampling from a river or stream take the
sample as near as possible to the main flow and
not too close to the edge where the water may be
still and unrepresentative of the sample as a whole
• Rinse any sample container repeatedly with
the sample to prevent any cross contamination
from previous samples
• Once collected the sample must be processed
immediately or as quickly as possible, especially
for highly reactive species such as chlorine for
example. The use of a portable field test kit
makes this possible. However if the delay
between sample collection and analysis is likely
to be several hours chill the sample to preserve
and prevent potential microbiological growth
• Samples containing solid particles can interfere
with photometric analysis. Either allow solids
to settle and decant the clear liquid or filter
the sample prior to analysis
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3.3 Starting up the Instrument
Power Supply
The Photometer 7500 is designed to be powered
either from alkaline batteries or via the USB port.
When operating on battery power, the battery
level is indicated on the Info Panel. A minimum
voltage of 3.0V is needed to operate the
photometer and a flashing battery symbol
indicates a critically low battery. Change batteries
immediately or switch to alternative USB power.
The Photometer 7500 will automatically power
down when power is no longer capable
of providing acceptable performance.
To power via the USB port, use the supplied
cable connected either to the mains adaptor
or a PC. The USB icon will appear when the USB
connection is made and battery power will no
longer be consumed.
The Photometer 7500 has a back-up battery
mounted internally to save instrument settings
and data during power loss and instrument
idle periods.
Replacing Batteries
The battery compartment is located on the base
of the instrument and secured by four screws.
Remove the cover and install a complete set of
new batteries, observing the correct polarity as
indicated. Use 3 x 1.5V 'AA' alkaline batteries
or equivalent. See Section 3.9 for more details.
To avoid corrosion damage through leakage,
remove batteries from the instrument if it is
to be stored or left unused for a long period.
Start-up Screen
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