Specifications

Instruction Manual Alpha DO 500
9
2.5 Display & Keypad
2.5.1 Display Overview
The Liquid Crystal Display (LCD) of the Alpha DO 500 Transmitter has two
alpha-numerical displays (Upper and a Lower).
x Upper display: Measured dissolved oxygen reading (in % saturation or
ppm or mg/l) is displayed when the Transmitter is in normal operation
(measurement) mode.
x Lower display: Measured temperature value is displayed when the
Transmitter is in normal operation (measurement) mode. In Calibration
mode, calibration points are displayed here.
The two displays indicate function names, options & settings in Setup mode.
Refer ‘Appendix 2 – Abbreviations Used in LCD’ for more details.
The LCD also consists of various mode indicators, status annunciators and
unit of measurement indicators.
%
SETUP MEAS
CAL
Upper Display
Lower Display
ERR
ATC
°C
READY
-
-
HOLD
ppm
mg/l
K=
Mode Indicators
MEAS
Measurement mode (Refer Section 3.1)
SETUP
Setup mode (Refer Section 5)
CAL
Calibration mode (Refer Section 4)
Status Annunciators
READY
Appears when the reading is stable
HOLD
Appears in Setup mode and Calibration mode to indicate that the relay function
is frozen
ATC
Appears when Automatic Temperature Compensation (ATC) is enabled.
Not visible when Manual Temperature Compensation (MTC) is enabled.
Flashes if the temperature probe is faulty in its ATC mode.
(Refer Section 5.4)
ERR
Appears when an error occurs
Buffer annunciator. Appears in calibration mode or viewing calibrated point
Electrode annunciator. Appears when viewing electrode properties or during
calibration error