4
The
HI 95721
is an auto diagnostic portable microprocessor meter that benefits from Hanna’s years of
experience as a manufacturer of analytical instruments. It has the advanced optical system based on
a special tungsten lamp and a narrow band interference filter that allows most accurate and repeatable
readings. All instruments are factory calibrated and the electronic and optical design minimizes the
need of frequent calibration.
With the powerful CAL CHECK™
validation
function you are able to validate good performance of
your instrument at any time. The validation procedure is extremely user friendly. Just use the exclusive
Hanna ready-made, NIST traceable standards to verify the performance of the instrument and
recalibrate if necessary.
All instruments are splash waterproof and the lamp and filter units are protected from dust or dirt by
a transparent cup. This makes the instruments fulfill field applications. Display codes aid the user in
routine operation. The meter has an auto-shut off feature that will turn off the instrument after 10
minutes of non-use or after 1 hour if left in the
calibration mode
.
The meter uses an exclusive positive-locking system to ensure that the cuvet is in the same position
every time it is placed into the measurement cell. It is designed to fit a cuvet with a larger neck
making it easier to add both sample and reagents. The cuvet is made from special optical glass to
obtain best results.
The
HI 95721
meter measures the
total iron
(Fe) content in water samples in the 0.00 to 5.00 mg/L
(ppm) range. The method is an adaptation of the USEPA METHOD 315B for natural and treated waters,
and Standard Method 3500-Fe B for water and wastewater.
The reagent contains both a reducing and a complexing agent: the first converts iron present in the
sample to the ferrous (Fe
2+
) soluble state; the second reacts with the ferrous ion to form the
characteristic orange-colored complex.
The reagent is in
powder form and is supplied in packets. The amount of reagent is precisely dosed to
ensure the maximum repeatability.
degree Celsius
US Environmental Protection Agency
degree Fahrenheit
High Range
milligrams per liter. mg/L is equivalent to ppm (part per million)
milliliter
°C
:
EPA
:
°F
:
HR
:
mg/L
:
mL
:
GENERAL DESCRIPTION
ABBREVIATIONS
17
or
• Press READ/TIMER and “SIP” will blink during
measurement.
• The instrument will show for three seconds the
CAL CHECK™ standard value.
Then the date of last calibration (e.g.: “01.08”)
appears on the display, or “01.01” if the factory
calibration was selected. In both cases the number
of the month is blinking, ready for date input.
Note
: if the display shows “ERR” the calibration
procedure failed. Verify that both CAL CHECK ™
Standards HI 95721-11 Cuvets,
A
and
B
, are
free from fingerprints or dirt and that they are
inserted correctly.
DATE INPUT
• Keep READ/TIMER pressed to scroll to the desired
month number (01-12).
• When the correct month has been set, press ZERO
to confirm. Now the display will show the day
number blinking. Keep READ/TIMER pressed to
scroll to the desired day number (01-31).
Note
: it is possible to change from
day
to
month
and vice versa by pressing ZERO.
• When both the day and month have been selected,
hold CAL CHECK for three seconds to store date
and calibration values. The instrument will show
for one second “Stor”, to confirm that the new
calibration data has been accepted.
• The instrument will return automatically to the
measurement mode by displaying "721" on the
LCD.
