Tektronix DMM4020 Digital-Multimeter, DMM, VFD-Multiple segment, 20000 counts CAT II 600 V DMM4020-A1 Data Sheet
Product codes
DMM4020-A1
DMM4020
Users Manual
3-18
Selecting a Function Modifier
This section describes the function modifiers available with the Meter. Function
modifiers are actions that the Meter performs on an input before a reading is displayed
(for example, a comparison to another value). Function modifiers can be used in
combination. See the “Using Function Modifiers in Combination” section later in this
chapter.
To use a function modifier, press a measurement function button to select that function,
To use a function modifier, press a measurement function button to select that function,
and then press the function modifier button to modify that function. (For example, press
D
D
to select dc voltage measurement, and then press I to select the Touch Hold
function to hold the results of your measurement). Note that modified readings are shown
on the primary display only.
After a function modifier is selected, pressing any function button turns off all modifiers,
After a function modifier is selected, pressing any function button turns off all modifiers,
causes the secondary display to go blank, and returns unmodified readings to the primary
display.
Relative Readings Modifier (REL)
The relative readings modifier displays the difference between the relative base and the
input measurement. For example, if the relative base is 15.000 V and the present input
measurement is 14.100 V, the display will show -0.900. Readings are shown on the
primary display.
XW
Warning
To avoid electrical shock or damage to the Meter, do not touch
the input terminals or test leads during measurement. Relative
readings may not indicate the presence of dangerous voltages
at the input terminals or test leads.
Note
Relative readings modifier cannot be selected if the display shows 0L
(overload) or is blank.
To make a relative reading, press T to select the relative readings modifier. The last
valid reading taken is stored as the relative base, the primary display zeroes out, and
RELX is shown on the primary display. (The secondary display is unaffected.)
To edit the relative base, use the number editor as described in the “Using the Number
To edit the relative base, use the number editor as described in the “Using the Number
Editor” section later in this chapter.
Selecting the relative readings modifier turns off autoranging and locks the present range.
Selecting the relative readings modifier turns off autoranging and locks the present range.
Make sure you are in the correct range before pressing T. If you press Uor V
after pressing T, the Meter exits the relative readings mode.
Decibels and Auto Power Modifier
The decibels modifier takes a voltage measurement, converts it to dBm (measure of
decibels relative to one milliwatt), and displays the result on the primary display.
Press dB to toggle in and out of the decibels modifier. When the decibels modifier is
Press dB to toggle in and out of the decibels modifier. When the decibels modifier is
selected, "dB" is shown on the primary display.
Decibels can be selected only when a voltage function is selected on the primary display
Decibels can be selected only when a voltage function is selected on the primary display
(volts ac, volts dc, or volts ac + dc). Decibels are always displayed in a single, fixed
range with 0.001 dB resolution. However, the basic measurement itself (volts ac for
example) autoranges.