Delta OHM HD2109.1, Operating Manual

Page: 8 / 46

HD2109
- 8 -
V2.4
KEYBOARD AND MENU DESCRIPTION
Foreword
The instrument keyboard is composed of single-function keys, like the MENU key, and double-
function keys such as the ON-OFF/Auto-OFF key.
In the double-keys, the function in the upper part is the "main function", while the one in the bottom
part is the "secondary function". When the instrument is in standard measurement mode, the main
function is active. In the menu or in conjunction with the FUNC key, the secondary function is en-
abled.
The pressing of a key is accompanied by a short confirmation beep: a longer beep sounds if the
wrong key is pressed.
Each key specific function is described in detail below.
ON-OFF/Auto-OFF key
The instrument is turned on and off using the ON/OFF key. The turning on enables all display seg-
ments for a few seconds. An auto-test follows which analyses the type of probe connected, and
reads its calibration information. In cases of a dissolved oxygen probe, the electrode calibration co-
efficient (SLOPE) is also displayed: this value must be between 0.500 and 1.500. A value close to
1.500 indicates an exhausted probe (see page 14 for how to proceed). Finally, the instrument is set
for normal measurement.
If a temperature probe is connected, the main line displays a dotted line (- - - -).
The connected probe's data are captured upon turning the instrument on: when the probe is
inserted into a functioning instrument, the "NEW_PROB_DET" message appears: turn the
instrument off and then back on again.
Replace the probes when the instrument is off.
+
Automatic turning off
The instrument has an
AutoPowerOff function that automatically turns the instrument off after about
8 minutes if no key is pressed during the intervening time. The AutoPowerOff function can be dis-
abled by holding the CAL/ key pressed down when turning the instrument on: the battery symbol
will blink to remind the user that the instrument can only be turned off by pressing the <ON/OFF>
key.