Hanna Instruments HI 98360 - Manual (Page 11)

11
To select the desired option press the 2nd then ATC key. The option tag
will blink for a few seconds then remain active on the LCD.
If temperature compensation is active, measurements are compensated
using a default temperature coefficient of 1.90 %/°C to the 25°C
reference temperature. This is a natural water tc value.
It is possible to view or select a different temperature coefficient (TC) in the
0.00 to 6.00 %/°C range by entering the setup mode and selecting the
“
tc” item (see SETUP section for details).
Notes: • The default compensation mode is Atc.
• If no temperature probe is detected, Atc mode can not be
selected and the instrument displays “ ----” on the secondary
LCD.
• If the temperature reading is out of the -20.0 – 120.0 ºC
range and Atc option is selected, the “ ºC” tag will blink and
the closest interval limit will be displayed.
• By pressing the ARROW keys the displayed temperature
value is changed. This value is used to compensate the
EC/TDS reading.
Temperature compensation is performed by means of the following formula:
Compensated conductivity = Measured conductivity
1+TC
25
(T-T
ref
)
where T is the measured temperature and T
ref
is the reference
temperature (20 or 25°C).
Note that if a solution has a temperature coefficient TC with T
ref
=25°C,
when changing the reference temperature to 20°C, the temperature
coefficient must be manually adjusted by the user according to the
following formula:
TC
20
=
TC
25
1-TC
25
/20
For example, TC
20
=2.10%/°C when TC
25
=1.90%/°C.
Always set reference temperature to 25°C when measuring TDS.
TDS MEASUREMENTS
Press the Range key while in EC range. The instrument will switch to TDS
measuring range. The TDS reading will be displayed on the primary LCD
and the temperature reading on the secondary LCD.
• If the reading is out of range, the full-scale value (100.0 for
MTC/ATC
mode or 400.0 for uncompensated TDS) will be displayed blinking.