Seeking a more reliable reading

Hi, all.
I have a ML 1400 ser A, using a 1762-IF4 analog input card.
I am using the -10 to +10v setting on I:1.0
When the analog sensor takes a process measurement, it sometimes reads low. I've entered some extra logic to track and catch 4 measurements in 1 second.
During the measurement, nothing physically changes, but sometimes the 4 readings are slightly different.
Is this just the limitations of the IF4 card? My readings are set to refresh at 130ms.
Any advise would be appreciated.

but sometimes the 4 readings are slightly different

Click to expand...

Define "slightly"

Maybe a little noise? (shielded cable? apply a filter to the input?)

The bad reading is usually 5%less. The sensor cable is NOT shielded, but there is only 120V nearby....and that is almost 2 feet away from the sensor or the cable.

Is there any way your sensor can be configured to output a 4-20ma signal? Direct voltage readings can be quite sensitive.

Hey, Madison, WI! Tomah, WI here!
I believe there is a way to "damn-up" the electrons by using a resistor to convert a 4-20mA into a 0-10volt signal...... But, I don't know of a way to do it vise-versa.

RobertB said:

Hey, Madison, WI! Tomah, WI here!
I believe there is a way to "damn-up" the electrons by using a resistor to convert a 4-20mA into a 0-10volt signal...... But, I don't know of a way to do it vise-versa.

Click to expand...

Before I went through the trouble of trying to convert, I would start with swapping the cable out for a shielded one. How long is the current cable you're using?

RobertB said:

The bad reading is usually 5%less. The sensor cable is NOT shielded, but there is only 120V nearby....and that is almost 2 feet away from the sensor or the cable.

Click to expand...

Start by fixing that problem. Both actually.