Hanna Instruments HI 255 User Manual
Page 10
10
If LOCK was pressed to freeze the LCD range and the reading went out of
range, the full-scale value of the frozen range will be displayed blinking.
The EC reading is affected by temperature.
Three options of compensating temperature are available, on EC measurement
mode.
Note: The compensation is referenced at the selected reference temperature
(see SETUP for details, page 31).
Automatic (Atc): The EC probe has a built-in temperature sensor; the
temperature value is used to automatically compensate the EC/TDS reading
(from 0.0 60.0 ºC).
Manual (Mtc): The temperature value, shown on the secondary LCD, can be
manually set with the ARROW keys. The ºC tag blinks when this option is active.
No Compensation (notc): The temperature
value is displayed, but is not taken into account
and ºC tag blinks with a higher frequency.
The reading displayed on the primary LCD is the
actual EC or TDS value. To select the desired
option, press the ALT&ATC keys until the option
is displayed on the LCD.
Note:
•
The default compensation mode is Atc.
•
If no temperature probe detected, Atc mode can not be selected
and the instrument displays ---- on the secondary LCD.
If temperature compensation is active, measurements are compensated using the
temperature coefficient (default value 1.90 %/ºC). To change the temperature
coefficient, enter the setup mode and select the tc item (see SETUP for details,
page 31). The current temperature coefficient can be quickly viewed by pressing
the ALT&TC keys. The value is briefly displayed on the secondary LCD.
If the temperature reading is out of 0.0 60.0 ºC interval and Atc option is
selected, the ºC tag will blink and the closest interval limit will be displayed.
Press the ARROW keys to change the displayed temperature value. This
value is used to compensate the EC/TDS reading.
TDS MEASUREMENTS
Press the ALT&MODE keys while in EC range. The instrument will switch to TDS
measuring range. A TDS reading will be displayed on the primary LCD and the
temperature reading on the secondary LCD.
ALT
ATC