40 34405A User’s and Service Guide
2Features and Functions
Math Operations and the Secondary Display
When a math operation is selected, the secondary display 
shows the result of the math operation or the value(s) being 
used by the math operation. For example, a typical primary 
display showing the Limit math operation for DCV 
measurements and a secondary display showing a HI limit 
exceeded is:
Repeatedly pressing  cycles through the secondary 
display choices for the present math operation as shown in 
the table below. (Reading is used in the table below to 
indicate the original measured reading value.)
mV DC
   Limit
Disp
Secondary Display
Math Operation Primary Display
Default Secondary
Display
Press Disp 
Key Once
Press Disp 
Key Twice
Press Disp
Key Three Times
Press Disp 
Key Four Times
Null Nulled Reading Reference Value  Off
dBm dBm Present Reading R
REF
 Off
dB dB Present Reading dB Ref (in 
dBm)
 Off
Min/Max Reading Max value Min value  Avg value N (count) value  Off
Limit Reading PASS
HI
LO
HI Limit LO Limit Off
Hold Held Reading Present Reading  Off
34405A users guide.book  Page 40  Saturday, September 2, 2006  3:38 PM