Re: pasco light probe oscillations

[brian whatcott <inet@intellisys.net>]

At 18:02 4/17/98 +0200, you wrote:
> ... With the polaroids at some arbitrary position, and everything
> left untouched, the reading from the probe oscillates with a period of about
> 15s and an amplitude about 5%. This goes on consistently for hours....
> Does anyone have an explanation?
>
> Mark.
>
> Mark Sylvester

It could be a real effect or an artifact:
Real:
Intensity variation sampled at varying points on the line input power
(unlikely)

Artifact:
A/D chip is autozeroing or compensating, and you are intercepting a
variable point on the drift or auto zero cycle with your sampling period.
(I don't find this idea very satisfying either...)

Whatcott    Altus OK