I hope not! Where do you start with this one?
I guess in theory if you have a good DC source and an accurate meter
you should be able to get that accuracy. I don't think my DC source
was good enough to give me +/- 0.1%. The meter is probably going to
measure the DC component only so I also worry about any ripple. I
don't know what the scope will use when it does its cal. Does it
just take one sample?
--- In TekScopes@..., "david_c_partridge"
<david.partridge@...> wrote:
I'd more likely suspect the TDS320 acquisition board :-(
I think the approach of using an external supply and a 5? digit
meter should give >> 0.1% accuracy.
Dave
--- In TekScopes@..., "cmbath" <cmbath@> wrote:
I have a TDS320 scope which has failed calibration. After I try
to
do a voltage cal and follow the prompts on the screen a message
appears telling me that voltage calibration has failed.
Unfortunately I do not have a proper calibrator. I do have a
CG551AP
however this will only provide positive voltages with respect to
earth and is unable to produce the required 80mV and 15mV levels
required for the calibration. Because of this I am cheating to
try
and calibrate (at least remove the failed cal status for the
time
being) by using an accurate DC power source verified against a
precision multimeter which appears to be able to produce a
stable
voltage within 1% or so of that required not taking into account
the
inaccuracy of the meter which should be relatively low given it
is
a
5 ? digit DMM. Clearly this is not within the accuracy of the +/-
0.1% specified in the service manual.
I suspect that when I try to do the Cal the calibration constant
calculated by the instrument is outside the range set by the
factory
as being appropriate and that this has been caused because my
reference voltage not being good enough. Is this the case or do
I
have another problem with the instrument? Nowhere in the manual
does
it state why it fails the voltage calibration.
