User manual

In this section:
Relative ............................................................................. 6-1
Math calculations .............................................................. 6-3
dB commands ................................................................. 6-10
Relative
Use the REL (relative) function to null offsets or subtract a baseline reading from
present and future readings. When REL is enabled, subsequent readings will be
equal to the difference between the actual input value and the REL value.
You can define a REL value for each function. Once a REL value is established
for a measurement function, the value is the same for all ranges. For example, if
50V is set as a REL value on the 100V range, the REL is also 50V on the
1000V, 10V, 1V, and 100mV ranges.
Therefore, when you perform a zero correction, the displayed offset becomes
the reference value. Subtracting the offset from the actual input zeros the
display, as follows:
Actual input - Reference = Displayed reading
A REL value can be as large as the highest range.
Selecting a range that cannot accommodate the REL value does not cause an
overflow condition, but it also does not increase the maximum allowable input for
that range. For example, on the 10V range, the Series 3700 still overflows for a
12V input.
NOTE The various instrument operations, including REL, are performed on
the input signal in a specific, predetermined order. For example, if
both REL and MXB (a math operation) are enabled, the REL
operation will always be performed before MXB.
Section 6
Relative, Math, and dB