Hanna Instruments PCA 310 - Manual (Page 17)

17
METHOD OF ANALYSIS
Free available
chlorine oxidizes
the DPD indicator
reagent at a pH
between 5.5 and
6.0 to form a ma-
g e n t a - c o l o r e d
compound. The
intensity of the re-
sulting color is
proportional to
the concentration
of chlorine in the
sample. The pur-
pose of the buffer
solution is to
maintain the
proper pH.
To measure total
residual chlorine
(free available
chlorine plus com-
bined chlorine) the PCA adds potassium iodide. The chloram-
ines in the sample cause iodide ions to become iodine which
then act with free chlorine to oxidize the DPD indicator. After
the chemical reaction is complete, the optical signal at 555
nm is compared to the signal measured through the sample
(before the reagents were added). From these measurements
chlorine concentration is calculated.
pH AND TEMPERATURE MEASUREMENT
The HI 1005 pH/temperature probe provides at the out port
a potential proportional with the pH. The temperature is mea-
sured with PT100 platinum sensor.
For increased accuracy the pH is corrected with temperature
and with the calibration coefficients. Up to 2 buffers can be
used for calibration.
The temperature can be displayed in °C or °F.
The probe can withstand pressure up to 6 bar (87 psi).
ORP MEASUREMENT
The HI 2008 probe provides at the out port a potential propor-
tional with the ORP value. The value is directly displayed in mV.
The probe can withstand pressure up to 6 bar (87 psi).
FIL
REGULAT
T
OR
OR
OR
V VE
TER
TRAP
(OPTIONAL)
PRESSURE
OR
O DRAIN
SAMPLE
INLET
REAGENT
BOTTLES
DETECT
STIR BAR
MAGNET
DC
MOT
MOT
& REDUCER
PUMP
ROLLERS
SOLENOID
SAMPLE
AL
LED
SAMPLE OUTLET
PCA 301 REAGENTS HI 70460
TOTAL CHLORINE INDICATOR SOLUTION
R: - -
S: - -
ETICPCA30A
Contents:
p-Toluenesulfonic Acid (6192-52-5)
Water (7732-18-5)
FOR LABORATORY AND INDUSTRIAL USE ONLY
DO NOT FREEZE
STORE AT ROOM TEMPERATURE
KEEP CONTAINER TIGHTLY CLOSED
PCA 301 REAGENTS
HI 70461
TOTAL CHLORINE BUFFER SOLUTION
Xn: Harmful R: 22
S: 46 ETICPCA30B
FOR LABORATORY AND INDUSTRIAL USE ONLY
DO NOT FREEZE
STORE AT ROOM TEMPERATURE
KEEP CONTAINER TIGHTLY CLOSED
HARMFUL IF SWALLOWED.
IF SWALLOWED SEEK MEDICAL ADVICE IMMEDIATELY
AND SHOW THIS CONTAINER OR LABEL. Contents:
Lithium Bimaleate (unknown)
Lithium Maleate (unknown)
Water (7732-18-5)
PROBE
HOLDER
ORP probe
PH probe
SAMPLE
OUTLET