Advertisement
The Date Format can be set to DD/MM/YYYY or
MM/DD/YYYY as required. To select the required
format highlight the desired choice and press OK.
Time Out
When operating using battery power the
Photometer 7500 provides automatic power-off
as a power-saving measure. Three settings are
provided:
Normal 5 minutes
Long
15 minutes
Off
(disables Time Out)
The time intervals begin after the last key is pressed
or activity takes place.
Time Out is automatically disabled when the
instrument is powered by USB supply.
Back Light
The instrument display features a high intensity
backlight to support use in low light conditions.
The backlight is designed to use minimal energy
but activating the Backlight will naturally consume
battery power more rapidly. The settings available
for Backlight are:
Backlight Auto-Dim Backlight activates on any
key press and dims after
15 seconds automatically.
Backlight On
Backlight is on permanently
Backlight Off
Backlight is off permanently
LCD Contrast
In addition to the Backlight, the default contrast
setting for the display can be adjusted using the
up/down keys when light conditions are difficult.
The display provides a sequence of alternating
squares to give visual indication of the correct
settings to apply.
When complete/acceptable press the OK key.
Photometer 7500
Version
The serial number of the instrument and the
software version are displayed. The instrument
serial number will be required for technical
support and servicing/warranty and can also
be found on the base of the instrument.
3.5 Analysing Samples
The Photometer 7500 provides simple, accurate
and reliable analysis of key drinking water,
wastewater and process water parameters.
Selecting the required parameter and performing
the test are supported through on-screen prompts
and comprehensive test instructions.
The principle of photometric testing is based on the
absorption or scattering of a measured intensity
of incident light compared to the light intensity
reaching the detector array. The light intensity is
determined as Transmittance (%T) or Absorbance (A)
and compared to calibration tables stored within the
Photometer 7500. The stored calibration tables
convert %T or A to results in a variety of units
(mg/l, ppm etc.) as defined in Section 3.4.
Calibration tables are defined by Palintest based
on the measurement of reference standards using
Palintest reagents. To achieve the best quality
results there are a small number of care points:
1 Always use the provided light cap to prevent
ambient light affecting the results.
2 Ensure Sample and Blank cuvettes are clean, dry
and inserted correctly into the sample chamber,
using the allocated orientation mark to align.
3 Always blank the instrument with untreated
sample prior to analysis.
Additional guidance is provided in Section 3.8
Photometric Testing Hints and Tips
3
17 17
Advertisement
