Keison PFP7 Service manual

Flame Photometer
Models PFP7 and PFP7/C
Operating and Service Manual

1 PFP7/REV C/01-08
Safety
Please read this information carefully prior to installing or using this equipment.
1. The unit described in this manual is designed to be operated only by trained personnel.
Any adjustments, maintenance and repair must be carried out as defined in this manual
by a person qualified to be aware of the hazards involved.
2. It is essential that both operating and service personnel employ a safe system of work
in addition to the detailed instructions provided in the manual.
3. The covers of the unit should only be removed by personnel who have been trained to
avoid the risk of shock. At this point the unit must be disconnected from all services i.e.
gas and electric.
4. References should always be made to the health and safety data supplied with any
chemicals used. Generally accepted laboratory procedures for safe handling of
chemicals should be employed.
5. If it is suspected that safety protection has been impaired in any way, the unit must be
made inoperative and secured against any intended operation. The fault condition
should be reported immediately to the appropriate servicing authority. In all such reports
the serial number of the flame photometer must be quoted.
6. Please read the operating precautions in section 4.6.

2 PFP7/REV C/01-08
Contents:
SECTION 1 ..................................................................................................... 4
Introduction...............................................................................................................................4
1.1 Instrument description..................................................................................................4
1.2 Principles of operation .................................................................................................4
1.3 Specification.................................................................................................................6
SECTION 2 ..................................................................................................... 7
Installation.................................................................................................................................7
2.1 Services required .........................................................................................................7
2.2 Unpacking ....................................................................................................................7
2.3 Assembly......................................................................................................................8
2.4 Installation ....................................................................................................................9
2.5 Accessories................................................................................................................10
SECTION 3 ................................................................................................... 11
Analysis Preparation..............................................................................................................11
3.1 Calibration standards .................................................................................................11
3.2 Sample preparation....................................................................................................12
3.3 Dilution .......................................................................................................................13
SECTION 4 ................................................................................................... 14
Operation.................................................................................................................................14
4.1 Front and rear panel controls.....................................................................................14
4.2 Operation ...................................................................................................................16
4.3 Calibration: PFP7.......................................................................................................17
4.4 Calibration: PFP7/C ...................................................................................................19
4.5 Shutdown ...................................................................................................................19
4.6 Operating precautions................................................................................................20
4.7 Good practice guidelines ...........................................................................................20
SECTION 5 ................................................................................................... 21
Accessories ............................................................................................................................21
5.1 Water separator .........................................................................................................21
5.2 Compressor ...............................................................................................................21
5.3 Diluter.........................................................................................................................22
5.4 Datalogger .................................................................................................................22
Maintenance............................................................................................................................23
6.1 General ......................................................................................................................23
6.2 Weekly maintenance..................................................................................................23
6.3 Monthly maintenance.................................................................................................23
6.4 Six-monthly maintenance...........................................................................................24

3 PFP7/REV C/01-08
SECTION 7 ................................................................................................... 25
Trouble shooting ....................................................................................................................25
7.1 General ......................................................................................................................25
7.2 Unstable results .........................................................................................................25
7.3 Unable to set standard reading..................................................................................25
7.4 Non-linear results.......................................................................................................26
7.5 Flame will not light .....................................................................................................26
7.6 No electrical power ....................................................................................................26
7.7 No reading on display ................................................................................................27
7.8 Unable to set blank ....................................................................................................27
SECTION 8 ................................................................................................... 28
Service Information................................................................................................................28
8.1 Sample system description........................................................................................28
8.2 Combustion and ignition system description .............................................................29
8.3 Optical system description .........................................................................................30
8.4 Power supply description ...........................................................................................30
8.5 Signal processing description ....................................................................................33
Component replacement .......................................................................................................35
9.1 Chimney and optical components..............................................................................35
9.2 Power supply PCB .....................................................................................................39
9.3 Main PCB replacement ..............................................................................................40
9.4 Fuel solenoid replacement.........................................................................................41
9.5 Fuel needle valve.......................................................................................................42
9.6 Spark generator replacement ....................................................................................42
9.7 Air regulator assembly replacement ..........................................................................43
SECTION 10 ................................................................................................. 44
Spare parts..............................................................................................................................44
10.1 Minor spares kit (500 172) .........................................................................................44
10.2 Major spares kit (500 173) .........................................................................................44

4 PFP7/REV C/01-08
Section 1
Introduction
1.1 Instrument description
The PFP7 and PFP7/C are low temperature, single channel emission flame photometers
designed for the routine determination of sodium (Na) and potassium (K). Additional filters are
available for the determination of lithium (Li), calcium (Ca) and barium (Ba). Both versions are
fitted with automatic flame failure detection for user safety, making them ideal for use in clinical,
industrial or educational applications. The model PFP7/C is specifically designed for use in
clinical applications. The in-built lineariser circuitry enables readings of both Na and K, at normal
clinical serum concentrations to be displayed directly in mmol/l. Serum samples must be diluted
200:1 or 100:1 prior to presentation to the flame photometer. Jenway are able to offer a diluter
to enable this to be carried out efficiently and accurately.
1.2 Principles of operation
Flame photometry relies upon the fact that the compounds of the alkali and alkaline earth
metals can be thermally dissociated in a flame and that some of the atoms produced will be
further excited to a higher energy level. When these atoms return to the ground state they emit
radiation which lies mainly in the visible region of the spectrum. Each element will emit radiation
at a wavelength specific for that element. The table below gives details of the measurable
atomic flame emissions of the alkali and alkaline earth metals in terms of the emission
wavelength and the colour produced.
Element Emission Wavelength (nm) Flame Colour
Sodium (Na) 589 Yellow
Potassium (K) 766 Violet
Barium (Ba) 554 Lime Green
Calcium (Ca) 622* Orange
Lithium (Li) 670 Red
*Note: Calcium is measured by using the calcium hydroxide band emission at 622nm as the
Calcium main atomic emission occurs at 423nm.
Over certain ranges of concentration the intensity of the emission is directly proportional to the
number of atoms returning to the ground state. This is in turn proportional to the absolute
quantity of the species volatized in the flame, i.e. light emitted is proportional to sample
concentration.
It can be seen that if the light emitted by the element at the characteristic wavelength is isolated
by an optical filter and the intensity of that light measured by a photo-detector, then an electrical
signal can be obtained proportional to sample concentration. Such an electrical signal can be
processed and the readout obtained in an analogue or digital form.
A simple flame photometer consists of the following basic components:
a) The burner: a flame that can be maintained in a constant form and at a constant
temperature.
b) Nebuliser and mixing chamber: a means of transporting a homogeneous solution into
the flame at a steady rate.
c) Simple colour filters (interference type): a means of isolating light of the wavelength to
be measured from that of extraneous emissions.
d) Photo-detector: a means of measuring the intensity of radiation emitted by the flame.

5 PFP7/REV C/01-08
Figure 1.2.1: Schematic diagram showing the component parts of a flame photometer.
The analysis of alkali and alkaline earth metals by flame photometry has two major advantages:
i. Their atoms reach the excited state at a temperature lower than that at which most
other elements are excited.
ii. Their characteristic wavelengths are easily isolated from those of most other elements
due to wide spectral separation.
The analysis of Na, K, Li, Ba and Ca are typically determined at low temperatures, i.e. 1500-
2000°C, therefore suitable fuel mixtures are propane/air, butane/air and natural gas/air.
Burner
Nebuliser
Mixing chamber
Filter
Flame Photodetector
Gas inlet
Drain
“U” tube
Waste
Readout
Amplifier
Lens
Air inlet
Burner
Nebuliser
Mixing chamber
Filter
Flame Photodetector
Gas inlet
Drain
“U” tube
Waste
Readout
Amplifier
Lens
Air inlet

6 PFP7/REV C/01-08
1.3 Specification
PFP7 PFP7/C
Ranges: - 120-160 mmol/l Na (linearised)
0-10.0 mmol/l K
Limits of Detection: Na ≤0.2ppm -
K ≤0.2ppm -
Li ≤0.25ppm Li ≤0.25ppm
Ca ≤15ppm Ca ≤15ppm
Ba ≤30ppm Ba ≤30ppm
Reproducibility: ≤1% Coefficient of variation (C.V.) for 20 consecutive samples
using 10ppm Na set to read 50.0.
Readings taken at 20 second intervals.
N.B. C.V. is defined as: the sample standard deviation X 100
mean reading
And sample standard deviation as:
Where x is the reading, x is the mean readings of the series and n is
the number of readings.
Linearity: Better than 2% when concentration of 3ppm Na and K and 5ppm Li
are set to read 100.
Specificity: Interference from Na, K and Li when equal in concentration to the
test element will be less than 0.5%.
Stability: Better than 2% over 5 minutes when continuously aspirating 10ppm,
sample set to read 50.0.
Zero drift better than 2% per hour.
N.B. Note warm up requirement.
Sample
Requirements:
Between 2 and 6ml/minute.
Recorder Output: Nominal 1.00 volt for readout of 100.0.
Warm Up: The flame must be alight for at least 15 minutes to ensure
achievement of the above stated specifications.
Services: Electrical: 90-125V or 190-250V @ 50/60Hz.
Air: Moisture and oil-free.
6 litres/minute at 1kg/cm
2
(14psi).
Fuel: Propane, butane, natural gas or L.P.G.
Operating
Environment:
15ºC to 35ºC
Size: 420 x 360 x 300mm
Weight: 8kg
(x-x
2
)
n-1
√
(x-x
2
)
n-1
√
(x-x
2
)
n-1
√

7 PFP7/REV C/01-08
Section 2
Installation
2.1 Services required
The fuel and air supplies to the instrument must be clean and dry and supply pressures
regulated within the limits specified. Any contamination, moisture or variation in supply pressure
will directly affect the performance of the instrument.
NOTE: The instrument will only operate with the correct type of air compressor and gas
regulator.
2.1.1 Voltage
90 - 125V or 190 - 250V @ 50 or 60Hz.
2.1.2 Fuel
•Propane or butane regulated to 10-15 inches water gauge (0.36-0.54psi or 0.025-
0.038kg/cm
2
).
•Natural gas at mains pressure between 3 and 10 inches water gauge (0.11-0.36psi or
0.0076-0.025kg/cm
2
).
•L.P.G. as for propane.
•Suitable regulators are available from Jenway; refer to Section 2.5.
2.1.3 Air
A supply of dry, clean and pulse-free air at a pressure between 14 and 30 psi (approx. 1-2
kg/cm
2
) at 6 litres/minute is required. A suitable compressor and water separator are available
from Jenway; refer to Section 2.5.
2.1.4 Drain
The instrument will need to be sited near a drain or sink to enable disposal of waste liquid. A
suitable receptacle can be utilised if provision is made for easy disposal of its contents.
WARNING: The waste liquid will still contain any hazardous materials that were in the original
samples and should be handled and disposed of with the same care. Waste liquid should
always be considered to be of a pathogenic nature where the instrument is used in a clinical
environment.
2.2 Unpacking
Remove the instrument from the packaging and ensure the following items are present:
Part Code
Model PFP7 or PFP7/C Flame photometer
Auxiliary power plug 009 035
Mains cable with connector (plug optional as ordered) 013 046
Nebuliser inlet tube (500mm) 500 193
Gas tube, low pressure (2 metres) 500 191
Silicon rubber tube (drain) 023 003
Air tube (2 metres) 500 192
Nozzle 1: gas 026 012
Nozzle 2: air 026 013
Allen key, 2.5mm 060 037
Adjustable hose clip 060 083
Drain trap 500 018
Drain trap clip 500 114
Nebuliser cleaning wire 500 194
Any shortages or damage should be reported immediately to the manufacturer or local
distributor.

8 PFP7/REV C/01-08
2.3 Assembly
Place the instrument on a bench and proceed as follows (see Figures 2.3.1 and 2.3.2 below).
1. Take the mixing chamber assembly and ensure that the fluted burner (1) is in place
(remove the retaining tape); offer up to the chimney. Look down the chimney and
ensure that the burner locates centrally in the inner chimney. Screw the locking ring (2)
onto the threaded boss provided and tighten until finger tight, ensuring that the mixing
chamber is at right angles to the side of the instrument.
2. Fit the nebuliser (3) into the end cap and screw on the tube (4) provided. Ensure that
the sealing olive is fitted correctly between the nebuliser and the screw on connector.
3. If natural gas is to be used, remove the restrictor (5) fitted into the end of the fuel inlet
(6) on the mixing chamber. The restrictor should remain in place if butane, propane or
L.P.G. is to be used as fuel. Keep the restrictor screw in case of any future change in
gas supply. Push the fuel tubing onto the fuel inlet connector (7). This tube does not
need securing.
Figure 2.3.1: Assembly of the mixing chamber, burner and nebuliser.
4. Take the drain trap clip (8) and, with the screw provided, fix to the hole situated at the
chimney end of the rear panel. Fix a length of silicon rubber tubing (9) onto the side port
on the drain trap such that it is long enough to reach either the sink or the waste
receptacle to be used. Fit the drain trap into the clip on the rear panel and run the short
piece of tubing (10) from the bottom of the drain trap to the drain trap outlet (11) on the
bottom of the mixing chamber. This tube can be pushed on and does not need
securing.
1
2
3
5
6
(4)
(7)
1
2
3
5
6
(4)
(7)

9 PFP7/REV C/01-08
Figure 2.3.2: Rear panel showing the drain trap, air and fuel tubing.
2.4 Installation
WARNING The exhaust gases from the chimney are very hot. No
obstruction should be placed above the instrument and the
instrument should be located in a position that makes
accidental contact with the chimney or its exhaust unlikely.
The instrument needs to be operated in a well-ventilated room
(although very strong draughts should be avoided).
Ensure the air tubing is routed away from sources of heat.
Fit the air and fuel inlet connectors to the ports provided on the rear of the instrument.
1. Fit the appropriate lengths of tubing to the connectors (12 and 13) and secure with the
screw clips provided. Run the tubing to the air and fuel supplies to be used.
NOTE: The maximum inlet pressure and regulation requirements are defined
in Section 2.1.
Turn on the fuel supply at the cylinder or source and check all fuel joints for leaks by
using soap solution.
2. Check the position of the voltage selector switch (14) on the rear panel and the value of
the fuse FS1. If necessary, adjust to suit your supply voltage. If necessary connect a
4
7
8
9
10
12
13
14
11
15a
15b
4
7
8
9
10
12
13
14
11
15a
15b

10 PFP7/REV C/01-08
suitable plug to the 3-pin AC supply lead. The colours of the wires conform to the
internationally recognised standard such that:
BROWN LIVE
BLUE NEUTRAL
GREEN/YELLOW EARTH
IMPORTANT – THE INSTRUMENT MUST BE EARTHED.
The green/yellow wire in the AC supply must be connected to a properly grounded
terminal.
If a compressor and/or pen recorder is to be run directly from the instrument then they
should be wired to the plugs provided and connected to the POWER OUT sockets (15a
and 15b).
Press the power switch on the front panel. The digital readout should be illuminated.
3. Fill the centre tube of the drain trap and the connecting silicon rubber tubing to the
mixing chamber with deionised water. Check that no air bubbles are trapped in this tube
and that it flows and runs to waste freely. Ensure that the drain trap is pushed
completely down on its clip.
2.5 Accessories
Always use recommended spares and accessories. Even if an alternative part may appear
obviously suitable there may be some minor variations in specification that could degrade the
performance of the instrument.
Accessory Part Code
Model 8515 air compressor (220V 50Hz) 535 001
Model 8516 air compressor (110V 60Hz) 535 002
Dilutor 230V
Dilutor 110V
037 001
037 002
Analogue to RS232 Data Logger 037 501
Calcium filter 500 125
Lithium filter 500 126
Barium filter 500 127
Butane regulator 500 178
Propane regulator 500 179
Natural gas regulator 500 180
Water separator (small) 500 176
Water separator (large) 500 177
Dust cover 500 134
Cleaning solution (1 litre) 025 171
Minor spares kit 500 172
Major spares kit 500 173

11 PFP7/REV C/01-08
Section 3
Analysis Preparation
3.1 Calibration standards
A comprehensive range of aqueous calibration standards is available from Jenway in both
industrial and clinical levels. These must be diluted to a suitable concentration for aspiration into
the flame (see Sections 3.3 and 4.3)
Clinical Standards (500ml) Part Code
1.00mmol/l Li 025 008
100mmol/l Na, 100mmol/l K 025 004
140mmol/l Na, 5mmol/l K 025 006
120mmol/l Na, 2mmol/l K 025 007
160mmol/l Na, 8mmol/l K 025 005
160mmol/l Na, 80mmol/l K 025 027
Industrial Standards (500ml) Part Code
1000ppm K 025 023
1000ppm Li 025 024
3000ppm Ba 025 025
1000ppm Na 025 021
1000ppm Ca 025 009
When preparing standards always observe the following:
1. Standards must always contain the constituents that are present in the samples in the
same concentration ratios; i.e. if samples are prepared in 0.05M HCl then the standards
should also contain 0.05M HCl.
2. Always ensure that the standards encompass the expected range of the sample
concentrations.
3. Standards should be prepared so as to ensure that the region in which measurements
are made coincide with the concentrations that produce the optimum performance from
the flame photometer, i.e…
•…when measuring sodium, the top standard is ideally 10ppm,
•…when measuring potassium, the top standard is ideally 10ppm,
•...when measuring calcium, the top standard is ideally 100ppm,
•…when measuring barium, the top standard is ideally 1000ppm,
•…when measuring lithium, the top standard is ideally 10ppm.
A minimum of four standards should be prepared to enable an accurate calibration
curve to be constructed.
NOTE: The blank used should contain all the constituents of the standard solutions except the
element being measured.
Since a flame photometer measures the concentration of the element itself in solution, standard
solutions prepared from the salts of sodium, potassium, lithium, calcium and barium must be
made up to contain the concentrations required in terms of the quantity of the elements.
Below are two examples of how to prepare standards of 1mg Na/100ml (10ppm Na) and 1mg
K/100ml (10ppm K).

12 PFP7/REV C/01-08
3.1.1 Sodium
Accurately weigh 0.634g of dry “Analar” quality NaCl, dissolve in pure deionised water and wash
into a 500ml volumetric flask. Fill to the mark with pure deionised water. To prepare the
standard solution for use with the flame photometer, this stock solution should be diluted 1 in
50.
Calculation:
Atomic weight Na = 23.0 Molecular weight NaCl = 58.46
Therefore, 0.634g NaCl contains 0.634 x 23 = 0.25g Na
58.46
Thus in 500ml of solution there is 250mg Na or 50mg Na/100ml.
Diluting 1 in 50 gives a standard of 1mg Na/100ml = 10ppm Na.
3.1.2 Potassium
Accurately weigh 0.477g of dry “Analar” quality KCl, dissolve in pure deionised water and wash
into a 500ml volumetric flask. Fill to the mark with pure deionised water. To prepare the
standard solution for use with the flame photometer, this stock solution should be diluted 1 in
50.
Calculation:
Atomic weight K = 39.1 Molecular weight KCl = 74.56
Therefore, 0.477g KCl contains 0.477 x 39.1 = 0.25g K
74.56
Thus in 500ml of solution there is 250mg K or 50mg K/100ml.
Diluting 1 in 50 gives a standard of 1mg K/100ml = 10ppm K.
3.1.3 Storage
Store solutions away from direct sunlight in a cool place, ideally at temperatures below 25ºC.
Glass containers should not be used for storage as they can affect the sodium concentration
levels. Standards should be stored in sealed, plastic vessels and in high concentrations, (e.g. as
a stock 1000ppm solution) and dilutions prepared as required. The long-term storage of low
concentration standards is not recommended due to degradation of ionic species.
3.2 Sample preparation
There are several practical points regarding sample preparation, which should be adhered to in
order to achieve the required accuracy in your analysis:
1. Avoid handling samples with fingers. This leads to serious contamination, e.g. if a finger
is immersed in 20ml of deionised water the resulting Na concentration will exceed that
of a 10ppm standard.
2. All analyses involve the use of a diluent, which is almost always deionised water. This
should be of the highest quality for accurate flame analysis. Sodium, potassium and
calcium are present in high concentrations in tap water and thus efficient deionisation is
essential.
3. Species that cause interference should be removed from samples or the equivalent
concentration of the interferant should be present in the standards so as to avoid
erroneous results, e.g. if a sample of approximately 10ppm Na contains approximately

13 PFP7/REV C/01-08
1000ppm Ca, then Na analysis can only be achieved by removing the Ca with
oxalate/oxalic acid or ensuring all standards contain 1000ppm Ca.
4. Always try to follow a well-documented analytical procedure, which should contain
information pertaining to interference removal when applicable.
5. Standards and samples should not be exposed to the atmosphere for long periods due
to contamination from airborne particles and the evaporation of the solvent that could
lead to elevated concentrations.
6. When in doubt about the equipment or application, the operator should contact Jenway
for advice.
3.2.1 Sample extraction
A number of methods for extracting sodium, potassium, lithium, calcium and barium from a wide
variety of raw materials may be obtained by contacting the technical support helpline at
[e-mail].
The sample must be in the form of an aqueous solution, with no solid matter present, to be
suitable for direct introduction into the flame photometer. This is achieved by:
•Extracting the salts from solid samples using deionised water or suitable extractants
e.g. saturated CaSO
4
for sodium in soil. Extraction is more successful using a blender,
macerator or shaking machine.
•If the sample is organic then the organic material should be removed by ashing. The
remaining oxides are then dissolved using strong acids.
•Filtration/centrifugation is used to remove solid debris.
When aqueous, the sample can then be diluted to a known, accurately measured volume using
deionised water. If it is a concentrated sample then the dilution ratio should be increased. If the
sample concentration is low then a small volume of diluent and initial extractant should be used.
Whichever method of extraction is used, the resultant solution must always be free of any
particulate matter that may cause blockages in the nebuliser capillary tube.
3.3 Dilution
In order to obtain samples and standards of the right concentration for aspiration into the flame,
various levels of dilution will often be necessary. Good quality deionised water should normally
be used for carrying out these dilutions and it is recommended that the same batch of water
should be used for diluting the samples and standards. More information on typical dilution
ratios is given in Section 4.3.

14 PFP7/REV C/01-08
Section 4
Operation
4.1 Front and rear panel controls
4.1.1 Front panel controls
Figure 4.1.1: Front panel
power A two-position rocker switch which controls the AC supply of the
instrument. Any accessories connected to the auxiliary POWER OUT
sockets on the rear panel are also controlled by the front panel power
switch.
ignition A spring loaded switch which, when depressed, will cause an electrical
discharge between the ignition electrode and the burner unit, thereby
causing fuel ignition.
d.p. This switch controls the position of the decimal point.
fuel A fine needle valve that controls the flow of fuel and enables optimum
flame conditions to be set.
blank This control sets zero (or low reading) when a blank standard is
aspirated.
sensitivity:
fine and coarse
Two controls which are used in conjunction to set the digital readout to an
appropriate number when a calibration standard is aspirated.
filter select A five position control which will select the appropriate optical filter for the
element being determined.
NOTE: positions 1, 2 and 3 will normally be blank unless optional
filters (Ca, Ba or Li respectively) have been fitted.

15 PFP7/REV C/01-08
4.1.2 Rear panel controls
Figure 4.1.2: Rear panel
Voltage
selection
A two-position switch marked 230 and 115. These positions allow
operation from voltage supplies 190-250 volts and 90-125 volts
respectively at either 50 or 60Hz.
WARNING: when adjusting the operating voltage it may be
necessary to change the top fuse as indicated on the rear panel.
Fuses Two fuses are fitted to the instrument. FS1 is the primary fuse provided to
give protection to the instrument and any accessories connected to the
power out sockets. FS2 is to protect the electronic circuitry in the PFP7.
Both FS1 and FS2 should be of an anti-surge type.
POWER IN A three pin receptacle for the AC mains supply
POWER OUT Two three pin sockets for flame photometer accessories such as a
compressor and a pen recorder. The power from these sockets is
controlled by the instrument power switch on the front panel.
RECORDER Two 4mm sockets which will provide an analogue signal of approximately
1 volt when the readout is 1000 digits or 100.0, 10.00 and 1.000.
FUEL GAS 1/4” connector for fuel tubing.
IMPORTANT: Fuel supply must be regulated to 10-15 inches water
gauge (0.36-0.54psi or 0.025-0.38kg/cm
2
). See section 2.1.2 for
information on different fuel types.
AIR 5/16” connector for air tubing.
IMPORTANT: Air pressure on the inlet to the instrument must not
exceed 30psi (2kg/cm
2
). See section 2.1.3.

16 PFP7/REV C/01-08
4.2 Operation
1. Ensure that the drain trap is pushed fully down on its clip. Ensure that the drain trap has
solution in it and that no air locks are present. If necessary, purge by adding deionised
water and allowing the surplus to run away.
2. Close the fuel valve by turning fully clockwise. To avoid damaging the valve, it should
not be forced.
3. Turn the fuel valve the required number of turns anti-clockwise depending on the fuel
being used.
Fuel Number of turns
Propane 3
Butane 4
Natural gas Fully open
L.P.G. 3.5
4. Turn on the fuel supply at source i.e. cylinder.
5. Switch on electrical power by depressing the power switch. If the air compressor is
powered separately, switch on the air compressor. Ensure that air is present by
listening for the hissing created as it passes through the nebuliser.
6. Depress the ignition switch and hold down. Watch the FLM indicator in the display
window. When this indicator is illuminated the flame is alight and the ignition switch can
be released. If the FLM indicator does not light within approximately 20 seconds,
release the switch and open the fuel valve one turn. Allow the gas to disperse before
continuing. Depress the ignition switch for a further 20 seconds. This process may be
repeated until successful ignition occurs. If the fuel valve has to be opened more than 5
turns more than recommended above, refer to Section 7.5.
7. Set the filter select control to the desired position.
8. Aspirate deionised water and set the readout to zero by adjusting the blank control.
9. Aspirate a standard solution of slightly higher concentration than expected in the
samples to be tested. Adjust the fine and coarse control until a positive reading is
obtained. This is a nominal value to be used in optimising flame conditions.
10. Adjust the fuel valve in a clockwise direction until a peak reading is obtained.
NOTE: There is a time delay between adjusting the flow of fuel and seeing
the effect of the adjustment. A pause of a few seconds is therefore
necessary between making every fine adjustment.
The optimum flame conditions are different for Na and K and
retuning is necessary when switching between elements.
11. For optimum performance the instrument should be allowed 15 minutes to warm-up.
During this warm-up period a blank deionised water sample should be aspirated. It
should be noted that results, adequate for most purposes, can be obtained from switch
on, although standardisation settings will need frequent checking during the warm-up
period.

17 PFP7/REV C/01-08
4.3 Calibration: PFP7
It is important to understand that the principles of flame photometry are such that, over certain
concentration ranges, light emitted from the flame is directly proportional to the concentration
of the species being aspirated.
The graph below shows that the direct relationship between the flame emission and
concentration is only true at relatively low concentrations. Above these low levels the flame
begins to saturate and the flame emission ceases to increase in a linear relationship to
concentration.
Figure 4.3.1: Relationship between sample concentration and flame emission.
If the samples being analysed lie on the linear part of the curve then the user can take direct
concentration readings from the digital display. If, however, the concentration of samples are
above the levels shown on the graph then the user has the choice of either:
a. diluting the samples so that they lie on the linear part of the curve, or
b. constructing a calibration curve and relating the digital display reading to the
concentration by cross-reference to the curve.
A calibration curve is prepared using standard solutions containing known concentrations of the
elements to be determined and if necessary, other materials to ensure that the standard and
sample backgrounds match. The concentration range covered by the calibration curve will
depend upon the expected concentration of the samples so that the sample readings fall
somewhere in the middle of the calibration curve.
Once the calibration curve has been plotted, the readings for the sample solutions are
compared with the curve to allow the sample concentrations to be established.
It is important to realise that each element has its own characteristic curve and separate
calibration curves must be constructed.
If the same estimation is performed on a routine basis, the calibration curve need only be
prepared once and checked periodically. Instrument re-calibration is easily achieved by setting
the blank solution to read zero and the top standard to read the same value as it did when the
calibration curve was initially prepared. The graph in Figure 4.3.2 shows a typical curve
obtained when measuring in parts per million (ppm).
0
2
2
4
46
6
8
8
10
10 12
ppm
Readout
0
2
2
4
46
6
8
8
10
10 12
ppm
Readout

18 PFP7/REV C/01-08
Figure 4.3.2: Typical calibration curve measuring ppm.
Customers working in medical environments are quite likely to be using the S.I. unit of mmol/l to
report their results. The relationship between mmol/l and ppm is defined below:
Sodium Na 1ppm = 0.0435mmol/l 1mmol/l = 23ppm
Potassium K 1ppm = 0.0256mmol/l 1mmol/l = 39ppm
Lithium Li 1ppm = 0.1441mmol/l 1mmol/l = 7ppm
Calcium Ca 1ppm = 0.0250mmol/l 1mmol/l = 40ppm
This relationship means that Na and K samples in the normal clinical range of 136-145mmol/l
Na and 3.5-5.0mmol/l K should be pre-diluted 1 in 100 or 1 in 200 to get optimum results from
the flame photometer.
1. Aspirate a blank solution and set the readout to 000 using the blank control.
2. Aspirate the highest standard solution and set the readout to an appropriate reading
using the fine and coarse sensitivity controls. Re-check the blank setting and adjust if
necessary.
3. Aspirate the remaining standard solutions (if used) to construct the calibration curve and
note the results.
4. When the blank and standards are set, unknown samples can be aspirated and the
results noted, either directly from the instrument readout, or by deriving the
concentrations from the calibration curve.
5. Calibration needs to be checked periodically by aspirating the blank and standard
solutions. Initially this check should be carried out after every 10 samples. Experience
and increased confidence in the PFP7 will enable you to best judge the frequency of
this check.
6. The decimal point (d.p.) switch can be set to illuminate the decimal point in any
significant position. This should be chosen to give sufficient resolution for the test
required.
0
5
5
10
10 15
15
20
20
25
25
ppm
Readout
Unknown sample
reads 20 and can
be seen to have a
concentration of
approx. 16.5ppm
Calibration points
at 5,10,15,20 and
25ppm
0
5
5
10
10 15
15
20
20
25
25
ppm
Readout
0
5
5
10
10 15
15
20
20
25
25
ppm
Readout
Unknown sample
reads 20 and can
be seen to have a
concentration of
approx. 16.5ppm
Calibration points
at 5,10,15,20 and
25ppm

19 PFP7/REV C/01-08
4.4 Calibration: PFP7/C
When using the PFP7/C, a calibration curve is not required as the display is calibrated in direct
concentration units. Therefore only one top standard is required to enable this calibration to be
performed .
Installation and set-up procedures should be carried out as for the standard Model PFP7.
NOTE: The Model PFP7/C allows direct readout of Na and K concentration
in serum samples. Na levels in urine samples may also be read
directly from the display, although K levels in urine can only be
determined by plotting a calibration graph (refer to standard PFP7
calibration).
Samples of both serum and urine should be diluted 1 in 100 or 1 in
200 to obtain optimum results from the flame photometer.
To calibrate the unit for clinical use the following steps should be carried out:
1. Aspirate deionised water and set the display to read zero.
2. Select the appropriate element (Na or K) on the filter select control and the position of
the decimal point using the d.p. switch.
3. Aspirate the required standard, e.g. 140mmol/l Na, 5.0mmol/l K which has been pre-
diluted at least 1 in 100 and set the display reading accordingly using the fine and
coarse sensitivity controls.
4. Adjust the fuel valve in a clockwise direction until a peak reading is obtained. Re-set the
display reading accordingly for the standard being aspirated.
NOTE: There is a time delay between adjusting the flow of fuel and seeing
the effect of the adjustment. A pause of a few seconds is therefore
necessary between making every fine adjustment.
The optimum flame conditions are different for Na and K and
retuning is necessary when switching between elements.
5. Re-check the zero setting and adjust if necessary.
6. Aspirate the pre-diluted sample and note the reading.
7. Calibration needs to be checked periodically by aspirating the blank and standard
solutions. Initially this check should be carried out after every 10 samples. Experience
and increased confidence in the PFP7/C will enable you to best judge the frequency of
this check.
4.5 Shutdown
1. Aspirate deionised water for at least ten minutes.
2. If the shutdown is short term i.e. the instrument is to be used again the same day/shift, it
is adequate to remove electrical power from the unit by depressing the power switch.
This will safely extinguish the flame.
3. If the shutdown is longer term or if the laboratory is likely to be left unattended during
the shutdown, then the fuel supply should be turned off at source; wait for the FLM
indicator to extinguish and then turn off the power. This ensures that there is no gas left
in the tubing to the unit.