Operator`s manual

Signametrics 32
.0 DMM Operation and Measurement Tutorial
.1 Voltage Measurement
ve
Making Voltage Measurements is straightforward. The following tips will allow you to make the most accurate
Whe per wire shorting plug
a
uality probes that are optimal for low-
vel measurements.
V
ring meters, the SM2060 may
ible, should have the NEUTRAL or GROUND attached to the SM2060 V,Ω - terminal.
See Figure 4-1, below. This prevents any “Common Mode” problems from occurring (Common Mode refers to
ound.) Common Mode problems can result in noisy readings, or even
ntrol
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Most of the SM2060 measurement functions are accessible from the Windows Control Panel (Figure above). All of
the functions are included in the Windows DLL driver library. To gain familiarity with the SM2060 series DMM’s,
run the Windows ‘SETUP.EXE’ to install the software, then run the DMM, as described in the previous section.
This section describes in detail the DMM’s operation and measurement practices for best performance.
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Measures from 0.1 µV to 330 VDC or 250 VAC. Use the V, Ω + and V, Ω - terminals, being certain to always lea
the I+, I- and DIN-7 terminals disconnected. Use the AC/DC button on the Control Panel to switch between AC
and DC.
voltage measurements.
4.1.1 DC Voltage Measurements
n making very low-level DCV measurements (<1 mV), you should first place a cop
across the V, Ω + and V, Ω - terminals and perform Relative function to eliminate zero errors before making your
measurements. A common source of error can come from your test leads, which can introduce several µVolts of
error due to thermal voltages. To minimize thermal voltaic effects, after handling the test leads; you should wait
few seconds before making measurements. Signametrics offers several high q
le
Note: The SM2060 front panel powers up in DCV, 0.5s aperture, 240 V range. If the DMM is operated in
Autorange, with an open input, The DMM will keep changing ranges. This is perfectly normal with ultra high
impedance DMM’s such as the SM2060. The virtually infinite input impedance of the 240 mV and 2.4 V DC
ranges causes this phenomenon. On these ranges, an open input will read whatever charge is associated with the
signal conditioning of the DMM. As this electrical charge accumulates, the SM2060 will change ranges.
4.1.2 True RMS AC Voltage Measurements
ACV is specified for signals greater than 1mV, from 10 Hz to 100 kHz. The ACV function is AC coupled, and
measures the true RMS value of the waveform. As with virtually all true-RMS measu
not read a perfect zero with a shorted input. This is normal.
ACV measurements, if poss
floating the SM2060 V,Ω LO above Earth Gr
cause the PC to hang-up under high V X Hz input conditions. In many systems, grounding the source to be
measured at Earth Ground (being certain to avoid any ground loops) can give better results.
he settling time and low end bandwidth of the RMS function are effected by the status of the Fast RMS co
T
circuit. When fast RMS is selected, the RMS settling time is about 10 times faster, but the low end frequency is
significantly increased.