ISSUE NO. V1.3 DATE 12/12/00
13
The instrument will now take a measurement and the message
Performing measurement
appears on the display. The result will then
appear on the display in the selected colour scale. If this is not the correct scale then reselect the scale required according to section
‘Colour scale’
. Once chosen, the instrument will calculate the result in the new scale.
To store the measurement as a standard for DELTA E calculations, press the
[
↵
↵↵
↵
]
key after the measurement has been completed.
6. Recording
results
Printing results
Set the appropriate printer options as described in
‘Setting the operating parameters’
. Connect the cable from a standard Centronics
parallel printer to the PFX995/950 printer outlet. Press
[PRINT]
if results for one scale only are required.
Connecting to a computer
Only EN 60950 approved computers should be connected to the RS 232 port.
A software program that allows direct control of the Lovibond PFX995/950 from an IBM compatible computer can be purchased from the
supplier. This software pack is supplied with an RS232 lead.
Communication by default takes place at these settings: 9600 Baud, 1 Stop Bit, 8 Data Bits, NO Parity
7. Regular
Maintenance
Instrument cleaning
The Lovibond PFX995/950 instruments require minimal routine maintenance. However, any spillage on the instrument or in the sample
chamber must be cleaned immediately and regular cleaning is recommended to ensure accurate and repeatable measurements:
Sample chamber
The sample chamber windows should be cleaned, if they become contaminated, by using a suitable lens cleaner
or alcohol-based degreaser. Spillage can be removed from the chamber floor with a sponge and alcohol-based
degreaser.
Keypad & display
These should be kept clean with an alcohol-based cleaner to aid reading of the display and the keys.
Instrument housing
Clean with detergent in warm water. Abrasive cleaners must not be used.
Care of glass cells
Cells should be cleaned immediately after use and examined for cleanliness and flaws before further use; otherwise sample
transmittance values may be affected.
The cleaning process will depend on the nature of the sample. If necessary, immerse cells in a suitable strength, warm solution of
detergent for several hours. Remove any remaining deposits on the cell faces by washing in 5% hydrochloric acid. When clean, rinse
thoroughly in distilled water and, finally, in ethanol or acetone, before allowing to dry.
To remove stubborn staining, immerse the cell in freshly prepared chromic acid and leave overnight. The cell should then be rinsed and
dried as above. Cells should not be allowed to dry out at any intermediate stage. Never attempt to clean the inside of cells with a cloth,
as this may crack the windows. When cells are not in use, store them where they are protected from accidental damage.
Checking measurements
A calibrated glass filter of known colour value is supplied for use as a checking measurement
standard. Although not a substitute for regular calibration, which uses a range of filters, this standard
provides the user with a method of demonstrating that the instrument is functioning correctly. The use
of this standard will provide the user with confidence that the instrument is continuing to function
within its specification.
The calibrated glass filter must be kept free from dirt and dust. The glass surfaces must never be
touched.
To conduct a checking measurement using the calibrated glass filter, carry out the following actions:
•
Ensure that the cell compartment is empty.
•
Perform a baseline measurement [ZERO]
•
Place the calibrated glass filter in the instrument as detailed in the diagram.
•
Select the colour scale specified on the Certificate of Conformity, which is supplied with the filter.
•
Press
[READ]
.
The measurement result will appear on the display. Check that the colour value falls within the tolerances specified on the Certificate of
Conformity. It is recommended that the filter be returned to Tintometer Ltd annually for re-certification.