Operator`s manual

The Min/Max box can be used to analyze variations in terms of Min, Max,
Percent and dBV. This display can be activated by selecting the
M
in/Max/Deviation from the Tools menue. For instance, testing a circuit
bandwidth with an input of 1V RMS, activate the Relative function with the
frequency set to 100Hz, than sweep gradually the frequency, and monitor the
percent deviation as well as the dBV error and capture any response anomalies
with the Min/Max display. The left display indicates peaking of 2.468% (0.21
dBV) and maximum peaking in the response of +56.24mV and a notch of –
10.79mV from the reference at 100Hz.
Aperture Box: Controls the SMU2060 reading aperture. As aperture decreases, the measurement noise
increases. For best accuracy set to the longest aperture acceptable for the application. Also consider the
line frequency (50/60 Hz) of operation when setting it, as certain apertures have better noise rejection at
either 50 or 60 Hz. (See “Specifications” for details.). When measuring RMS values, there is no point
setting the Read Interval (1/rate) to a value shorter than 0.16s since the RMS circuitry has a settling time
that is greater.
Range: Can be set to Autorange or manual by clicking on the appropriate range in the lower part of the
Windows panel. Auto ranging is best used for bench top application and is not recommended for an
automated test application due to the uncertainty of the DMM range, as well as the extra time for range
changes. Locking a range is highly recommended when operating in an automated test system, especially
to speed up measurements. Another reason to lock a range is to control the input impedance in DCV.
The 240 mV and 2.4 V ranges have virtually infinite input impedance, while the 24 V and 240 V and 330
V ranges have 10 M input impedance.
S_Cal: This function is the System Calibration that corrects for internal gain, scale factor and zero
errors. The DMM does this by alternatively selecting its local DC reference and a zero input. It is
required at least once every day to meet the SMU2060 accuracy specifications. It is recommended that
you also perform this function whenever the external environment changes (e.g. the temperature in your
work environment changes by more than 5C, or the SMU2064 on board temperature sensor indicates
more than a 5C change). This function takes less than a few seconds to perform. Disconnect all leads to
the DMM before doing this operation. Keep in mind that this is not a substitute for periodic calibration,
which must be performed with external standards.
ClosedLoop: This check box selection is used in conjunction with the AC and DC Voltage-Source
functions of the SMU2064. When checked, the DMM monitors the output level and continuously applies
corrections to the output level. When not checked, the DMM is a 12-bit source vs. 16 bits in the
ClosedLoop mode.
OpenCal: This check box selection is used in conjunction with inductance measurement. It is necessary
to perform Open Terminal Calibration using this control, prior to measuring inductance. This function
characterizes both the internal DMM circuitry as well as the probe cables. To perform OpenCal, attach the
probe cables to the DMM, leaving the other end of the probe cables open circuited. Then, activate the
OpenCal button.
Sources Panel: There are three function buttons in the Source group (SMU2064 only). The V, I, LEAK
buttons select one of three source functions, Voltage (DC and AC), IDC and Leakage. The Sources Panel
is automatically enabled when one of the source functions is enabled. It can also be invoked using the
Sources Panel selection under the T
ools menu. This panel allows the entry of values for all of the source
functions, including Leakage.
Signametrics 32