Hanna Instruments HI 255 - Manual (Page 11)

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• If the reading is out of range, the full-scale value (100.0 for Mtc/Atc mode
or 400.0 for actual TDS) will be displayed blinking.
• 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.
NaCl MEASUREMENTS
Press the ALT&MODE keys while in EC range until NaCl is displayed on the
LCD. The instrument will display the NaCl reading on the primary LCD and the
temperature reading on the secondary LCD line.
• If the reading is out of range, the full-scale value (400.0%) will be
displayed blinking.
TEMPERATURE MEASUREMENTS
To take temperature measurements while the instrument is in pH/ORP range,
connect the HI 7662 temperature probe to the appropriate socket.
Immerse the temperatureprobeinto the sample and allow the reading on
the secondary LCD to stabilize.
For EC/TDS/NaCl range, the HI 76310 probe has a built-in temperature sensor.
Note: • If the instrument is in pH/ORP range and the HI7662 temperature
probe is not connected, the “ºC” tag will blink (manual compensation)
even if EC probe is connected.
AUTORANGING
The EC and TDS scales are autoranging. The meter automatically sets the scale
with the highest possible resolution.
By pressing LOCK, the autoranging feature is disabled
and the current range is frozen on the LCD. The “Auto”
“Off” (autoranging disabled) tags will be displayed on
the LCD for a few seconds. To restore the autoranging option, press LOCK
again. The “Auto” “On” (autoranging enabled) tags will be displayed on the
LCD for a few seconds.
Note: Autoranging is automatically restored if the range is changed, if the setup or
calibration modes are entered and if the meter is turned off and back on again.