8
FRONT PANEL
1) Vial Holder
2) Dual Level Liquid Crystal Display (LCD)
3) Programs List
4) READ DIRECT, to perform measurement immediately
5) TIMER, to perform measurement after a preprogrammed
countdown
6) ZERO, to zero the meter prior to measurement
7) Program
t
and
s
, to select the desired parameter
8) ON/OFF, to turn the meter on and off
REAR PANEL
1) Power Supply 12 VDC 2.5 Watt
2) RS 232 Socket
3) Batteries Compartment
FUNCTIONAL DESCRIPTION
73
•
Wait for a few seconds and the
display will show “-0.0-”. Now the
meter is zeroed and ready for
measurement.
•
Remove the blank vial.
•
Place the sample vial into the holder
and push it completely down.
• Press READ DIRECT and "SIP" will blink on the display.
• The instrument directly displays concentration in
mg/L of phosphate
(PO
4
3-
) on the Liquid Crystal Display.
The method detects free (orthophosphate), condensed inorganic
forms (meta-, pyro- and other polyphosphates) and organic forms
of phosphates present in the sample.
• To convert the reading to mg/L of P
2
O
5
, multiply by a factor of
0.748.
• To convert the reading to mg/L of phosphorus (P) concentration,
multiply by a factor of 0.326.
Note
: for accurate measurements
1) wash glassware only with phosphate-free detergents
2) clean all glassware with 1 : 1 hydrochloric acid solution and rinse with
deionized water.
INTERFERENCES
Arsenate:
positive error
pH:
the sample should have a neutral pH
Temperature: the method is temperature sensitive.
It is recommended to add the Molybdovanadate Reagent
and to run measurements at T = 20 to 25 °C:
T < 20 °C causes a negative error
T > 25 °C causes a positive error
Turbidity:
turbidity and suspended matter in large amounts may
cause interference because the strongly acidic reaction
conditions may dissolve suspended matter or cause
desorption of phosphates from particles. Before
measurement, turbidity or suspended matter should
be removed by treatment with active carbon and by
prior filtration.
Phosphorus, Total HR