How to solve the fluctuation of vacuum signal range 0 -3V

[narithota]

how to use maltimeter

Hi
Iam measuring the vacuum signal range 0 -3v.
When I measured with maltimeter it is showing correct voltage corresponding to the vacuum.
But when I connect to the 74 HC4051 analog multiplexer the signal is fluctuating and Showing different values.
How to solve this problem
What precautions I have take while connecting the sensor signals to the ICs .
Thanks
Regards
chandu

 

[manish12]

Re: signal

Iam measuring the vacuum signal range 0 -3v.

what do you mean ?

where as 4051 req some time to stablez itself 680e will n effect.

 

[Project_maker]

signal

Because input impedance of 74HC4051 low enough to loading output of Vacuum source
Use JFET input Op-Amp as buffer amplifier connect between Vacuum source and 74 HC4051

 

[narithota]

Re: signal

hi

thanks for reply

What precautions we have take while connecting the sensor signals to the ADCs.

regards

chandu