Re: measurement problem

Myauk wrote:
On Sep 10, 4:16 pm, René <rjz~nosp...@xxxxxxxxx> wrote:

On Tue, 9 Sep 2008 23:33:53 -0700 (PDT), Myauk

<aungkokot...@xxxxxxxxx> wrote:

I made a measurement using signal generator 33220A and AC level meter
34410A.

I generated 150 kHz/0 dBm with 600 ohms load setting. Then I tried to
measure with a level meter and there the meter reads 10 dBm!

Could anybody explain how it happens and how to solve it! I have
already checked with different terminations and load settings but the
results remains the same.

Will there be any reason apart from being a defective meter?

log(600/50) = 10.8 ..hmm..

--
- Blarp the Enigmatic


:)

I think I found the reason, I also need to set the reference load
resistance value for math calculation of dBm in AC Level Meter, see on
page 69: http://www.physics.brocku.ca/Courses/2P32/References/datasheets/34401A_UsersGuide_English.pdf.

dBm Measurements
The dBm operation calculates the power delivered to a resistance
referenced to 1 milliwatt.
dBm = 10 ´ Log10 ( reading2 / reference resistance / 1 mW )
Applies to dc voltage and ac voltage measurements only.
· You can choose from 17 different reference resistance values.
The factory setting for the reference resistance is 600W.
The choices are: 50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500,
600, 800, 900, 1000, 1200, or 8000 ohms.
· The reference resistance is stored in non-volatile memory, and does
not
change when power has been off or after a remote interface reset.
· Front-Panel Operation: After enabling dBm, you can select a new
reference resistance by pressing Shift > (Menu Recall). Turning
on the menu does not disable the dBm operation; the multimeter
will resume taking measurements when you turn off the menu.
4: dBm REF R (MATH MENU)

It is not a big issue but sometimes the multimeters having many
options makes me quite confused. It is the kind of task that I have
never worked on before.
However I enjoy working here in this new job as I have to deal with
those small little akward practical problems and I believe I will get
used to it with time.

Regards
"reference resistance is 600 WATTS"???????
.

Quantcast