User`s guide

Operation and Features 2
Math Operations
U3606B User’s Guide 63
Null
When making null measurements, also called relative, each
reading is the difference between a stored (selected or
measured) null value and the input signal. One possible
application is to increase the accuracy of a 2- wire resistance
measurement by nulling the test lead resistance. Nulling the
leads is also particularly important prior to making
capacitance measurements. The formula used for calculating
null measurements is:
The null value is adjustable. You can set it to any value
between 0 and ±120% of the highest range, for the present
function.
NOTE
• All math operations can be toggled off by pressing [Shift] > [Exit].
• All math operations are automatically turned-off when changing
measuring functions.
• Range changing is allowed for all math operations except for the Hold
function.
• For remote operation, refer to the CALCulate subsystem in the
U3606B Programmer’s Reference.
Result reading null value–=
NOTE
• Null can be set for both auto and manual range settings, but not in the
case of an overload.
• In resistance measurement, the U3606B will read a non-zero value
even when the two test leads are in direct contact because of the
resistance of these leads. Use the null function to zero-adjust the
display.
• In DC voltage measurement mode, the thermal effect will influence the
accuracy. Short the test leads and press [Null] once the displayed
value is stable to zero-adjust the display.
U3606-90054_UG_EN.book Page 63 Friday, July 11, 2014 5:12 PM