Hanna Instruments HI 99181 - Manual (Page 2)

• For a single-point calibration with buffers pH 4.01, 9.18 or
10.01, the meter automatically accepts the calibration when
the reading is stable; the meter will show on the primary display
the accepted buffer, with the message “OK 1” on the secondary
display, and an audible signal is produced.
If a single-point calibration with buffers pH 7.01 or 6.86 is
desired, then after recognition of the buffer press any key to
return to the pH measurement mode.
Note: It is always recommended to carry out a two-point calibration
for better accuracy.
• For a two-point calibration, place the probe in pH 7.01 (or pH
6.86) buffer first. After the calibration point has been accepted,
the “pH 4.01 USE” message appears. Place the sensor into the
second calibration buffer. The message is held for 12 seconds,
unless a valid buffer is recognized. If no valid buffer is recognized,
then the “---WRONG“ message is displayed. If a valid buffer
(pH 4.01, pH 10.01 or pH 9.18) is detected, then the meter
completes the calibration procedure. When the buffer is ac-
cepted, the LCD displays the accepted value with the “OK 2”
message on the secondary display. The meter then returns to
the normal measuring mode.
Note: When the calibration procedure is completed, the “Calibrated“
tag is turned on.
To exit calibration and reset default values
• After entering the calibration mode and before the first point is
accepted, it is possible to quit the procedure and return to the
last calibration data by pressing the
ON/OFF/MODE button.
The secondary LCD displays “---ESC“ for 1 second and the meter
returns to normal mode.
• To reset to the default values and clear a previous calibration,
press the SET/HOLD button after entering the calibration
mode and before the first point is accepted.
The secondary LCD displays “---CLR“ for 1 second, the meter
resets to the default calibration and the “Calibrated” tag on
the LCD disappears.
First time you use the instrument open the battery compartment
and put the batteries inside observing the polarity.
To connect the probe
With the meter turned off, connect the
HI 1414D/50 probe to the
DIN socket on the bottom of the meter by aligning the pins and
pushing in the plug. Tighten the nut to ensure a good connection.
Remove the protective cap from the probe before taking any
measurements.
To turn the meter ON and check the battery status
Press the
ON/OFF/MODE button until the display lights up. At
start-up, all the LCD segments are displayed for 1 second, then
the percent indication of the remaining battery life is displayed for
another second (E.g. “100 % BATT“). The meter then enters the
normal measuring mode.
Note: If the display needs to be checked, keep the ON button
pressed while turning the meter on. The meter will display
all segments as long as the button is pressed.
To freeze the display
While in measurement mode, press the
SET/HOLD button, “HOLD“
appears on the secondary display and the reading will be frozen
on the LCD (E.g. “pH 5.73 HOLD“). Press any button to return to
normal mode.
To turn the meter OFF
While in normal measurement mode, press the
ON/OFF/MODE
button. “OFF“ will appear on the secondary display. Release the
button.
The meter is provided with an acoustic signal active when a key is
pressed.
Notes: • When the meter detects the absence of a temperature
probe at its input, the message “Probe not connected“
appears on LCD and the Automatic Temperature
Compensation is turned off along with the “ATC“ tag.
In this condition, the secondary LCD displays “25.0°C
“ (“77°F“) blinking. When the probe is reconnected,
the “Probe not connected“ tag is turned off, the
temperature is displayed on the secondary display
and the “ATC“ tag is turned on.
• To clean the meter, do not use aggressive detergents.
It is recommended to use water.
• Make sure the meter has been calibrated before use.
• If the probe is dry, soak it in
HI 70300 storage solution for
30 minutes to reactivate it.
• For better result, before taking any measurement, wet the skin
portion to be tested with distilled water or HI 70960 electrolyte
solution.
• Place the flat tip of the probe that is wetted with the electrolyte
solution on the sample to be tested and wait until the “Not
Stable“ tag on the LCD is turned off.
• The LCD displays the pH value (automatically compensated for
temperature) on the primary LCD, while the secondary LCD
displays the temperature of the sample.
• After each measurement, it is recommended to clean the probe
tip with HI 70620 and HI 70621 Cleaning & disinfecting
solutions, to eliminate coatings and avoid cross-contamination.
• When not in use, switch the meter OFF and clean the probe
with HI 70620 and HI 70621 Cleaning & disinfecting
solutions before storing it.
pH calibration
For better accuracy, frequent calibration of the pH sensor with
the meter is recommended. In addition, the meter must be
recalibrated:
a) Before each set of skin measurements.
b) Whenever the pH electrode is replaced or stored for long
periods.
c) Where high accuracy is required.
• From normal mode, press and hold the ON/OFF/MODE button
until “OFF“ on the secondary display is replaced by “CAL“.
Release the button. Place the sensor into the first calibration buffer.
• The meter enters the calibration mode, displaying “pH 7.01
USE” (or “pH 6.86 USE” if the NIST buffer set was selected).
After 1 second the meter activates the automatic buffer recognition
feature. If a valid buffer is detected, then its value is displayed
on the primary display, and “REC“ appears on the secondary
LCD. If no valid buffer is detected, the meter keeps the “USE“
indication active for 12 seconds, and then replaces it with
“---WRONG“, indicating that the sample being measured is not
a valid buffer.
Setup mode allows the selection of the temperature unit and the
type of pH buffer set.
To enter the Setup mode, press and hold the
ON/OFF/MODE
button until “CAL“ on the secondary display is replaced by “TEMP“
and the current temperature unit (E.g. “TEMP °C“). Then:
•
for °C/°F selection, use the SET/HOLD button. After the
temperature unit has been selected, press
ON/OFF/MODE to
enter the buffer set selection mode; press ON/OFF/MODE
twice to return to the normal measuring mode.
• to change the type of calibration buffer set, after setting the
temperature unit, the meter will show the current buffer set:
“pH 7.01 BUFF” (for standard buffer set: 4.01/7.01/10.01) or
“pH 6.86 BUFF” (for NIST buffer set: 4.01/6.86/9.18). Change
the set with the
SET/HOLD button, then press ON/OFF/MODE
to return to normal mode.
BATTERY REPLACEMENT
The meter is supplied with batteries.
The meter displays the remaining battery percentage when turned
on. When the level is below 5%, the “
- + “ symbol on the LCD
blinks to indicate a low battery condition. If the battery level is low
enough to cause erroneous readings, the Battery Error Prevention
System (BEPS) turns the meter off. It is recommended to replace
the batteries as soon as the display will flash the battery symbol.
To replace the batteries, follow the next steps:
• Open the battery compartment cap (on the bottom of the
instrument).
• Remove old batteries.
• Replace new batteries observing the polarity on the rear of
the instrument.
• Close the battery compartment cap.
OPERATIONAL GUIDE pH MEASUREMENT & CALIBRATION METER SETUP