Metrohm 827 pH lab - Manual (Page 56)

8.3 Diagnosis
48
826/827 pH meter, Instructions for Use
AD converter test
The electronic components of the analog-digital converter are checked.
At the end the messages 'Init ADC ok', 'Comm.test ADC ok' and
'ADC Interrupt ok' should appear.
LC display test
With this test you can check that the LCD display is functioning proper-
ly. It consists of a sequence of individual tests which can be switched
forward with any key (except <QUIT>). After displaying the character
set the test must be terminated with <QUIT>.
key test
The correct functions of all the instrument keys can be checked here.
The instrument will respond to the pressing of each key by displaying
the corresponding key code. This test is terminated by pressing the
<QUIT> key twice.
Key Code
< > 2
<CAL> 5
<QUIT> 1
<OK> 7
<> 4
<> 6
<> 8
<> 3