Temperature Calibration (For Technical Personnel Only) - Hanna Instruments HI 931100 Instruction Manual

IONIC STRENGTH ADJUSTER (ISA)
It is recommend the use of HI 7090 ISA solution when the NaCl
concentration of the sample is lower than 5 g/L. In such case, the
calibration of the meters should be performed with standard solution
containing 2% of ISA.
ISA (Ionic Strength Adjuster) = 50% of NH
OH 4M (use 2mL of ISA every 100 mL of sample).
TEMPERATURE
The best working temperature is around 20-25°C (68-77°F).
For greatest accuracy, we suggest to perform the calibration of the
meter with standard solution at a temperature as close as possible to
the temperature of the sample (± 1°C/±2°F).
Na CONCENTRATION WITH HI 931100 AND HI 931102
It is always possible to determine the Na concentration by using the
formula:
X = X
Na NaCl
where
X = Na concentration
Na
and
X = NaCl concentration
NaCl
TEMPERATURE CALIBRATION
(for technical personnel only)
All the instruments are factory calibrated for temperature.
Hanna's temperature probes are interchangeable and no tempera-
ture calibration is needed when they are replaced.
If the temperature measurements are inaccurate, temperature
recalibration should be performed.
For an accurate recalibration, contact your dealer or the nearest
Hanna Customer Service Center, or follow the instructions below.
• Prepare a vessel containing ice and water and another one containing
hot water (at approximately 50 ºC or 122 ºF). Place insulation
material around the vessels to minimize temperature changes.
• Use a calibrated thermometer with a resolution of 0.1 ºC as a
reference thermometer. Connect the HI 7662 temperature probe
to the appropriate socket.
• With the instrument off, press and hold down the CAL & Setup
keys, then power on the instrument. The "CAL" tag will appear
and the secondary LCD will show "0.0 ºC". The primary LCD will
display the measured temperature or the "----" message, if the
measured temperature is out of range.
Cl 4M +50% of NH
4
• (23 / 58.4)
18
4