4 PRINCIPLE OF OPERATIONS
9070
4.
STD
↓
: Use this control in conjunction with SET VALUE (
⇑
and
⇓
arrows)
buttons to set the value of the standard solution into the instrument. The
minimum value that one can enter for a standard solution is 20ppb.
5.
ALARM 1/ALARM 2
°
: Use in conjunction with the SET VALUE (
⇑
and
⇓
arrows) buttons to set the values at which the alarm relays operate.
6.
TEMP
±
: Pressing STD and CAL together gives an indication of the
sample temperature in
°
C
7.
RESET
″
: Use this button to regain control of the instrument in the unlikely
event of a malfunction. For instance, if a high power supply transient
occurred. (One cannot see this button when the cabinet door is closed).
FIGURE 4.5 SIMPLIFIED BLOCK DIAGRAM
19
