Brian,

Thanks for the fast response.

But the definition that I get from the person who asked me is as per below:

Definition: Thermohydrograph is basically the its characteristics and behavior of the metal traces within the board during exposure to variation of heating temperatures.

Is his definition correct?? Or is he's trying to express his understanding as per above but used the wrong term?

Regards,

Jacob Pao

-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: Wednesday, October 11, 2000 5:33 PM
To: TechNet E-Mail Forum.; Pao, JacobKH
Subject: Re: [TN] Thermohidrograph

A thermohygrograph, which is what I assume you are meaning, is an
instrument to record the temperature and relative humidity. It usually
consists of a drum, rotating over 24 hours, on which is clipped a paper
chart, with two pens drawing squiggly lines, one attached to a bimetal
spiral for the temperature and the other to a hair hygrometer movement
for the humidity. Very useful for putting into rooms where you are
stencilling solder paste, etc. to check that the environment is
correctly controlled.

Brian

> "" wrote:
>
> Technetter,
>
> May I know what does the term "thermohidrograph" mean? Is it a test
> measurement for PCB?
>
> Regards,
>
> Jacob Pao