8" eTape Liquid Level Sensor

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theherschmeister
 
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8" eTape Liquid Level Sensor

Post by theherschmeister »

I ordered the 8" eTape Liquid Level Sensor
(http://www.adafruit.com/products/463) but it appears to have been defective
upon arrival. The output resistance does not correspond at all with the datasheet,
even when not submerged in water. I'm hoping to be sent a replacement.

NOTE: The order was not placed by me directly, so it won't show up under my account. I can provide the order number if necessary.

Thanks!

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adafruit_support_bill
 
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Re: 8" eTape Liquid Level Sensor

Post by adafruit_support_bill »

The output resistance does not correspond at all with the datasheet,
Can you be more specific? Please show how you have the sensor connected and the actual resistances you are getting.

theherschmeister
 
Posts: 4
Joined: Thu Jul 24, 2014 4:51 pm

Re: 8" eTape Liquid Level Sensor

Post by theherschmeister »

Thanks for your reply. I've taken some photos of what I'm seeing to help explain the issue.

I connected my multimeter to the middle 2 pins of the sensor. It actually seemed to be doing okay at first. Here it is before being submerged, providing just a bit more resistance than what I would expect from the data sheet:
http://i.imgur.com/do3dwfp.jpg

Next, I taped it into my reservoir (filled with distilled water at room temperature), making sure it was as straight as possible and not touching the sides:
http://i.imgur.com/s7sB51I.jpg

Here's the reading at around 7.5". Again, not too far off from the data sheet:
http://i.imgur.com/2U4eO5k.jpg

Now here's where the issue starts. As I lower the water level, the resistance barely changes and does not match the data sheet at all.
http://i.imgur.com/yuHaYOW.jpg
http://i.imgur.com/AYCIfuY.jpg
http://i.imgur.com/fk5dbSU.jpg

Even when the reservoir is empty, the resistance has barely changed:
http://i.imgur.com/2Ve8loG.jpg

This behavior matches exactly with what I experienced a few days ago when I first tried using this sensor. At that time, I also tried some voltage divider and temperature compensation configurations, but with no more success.

Any help you can provide would be most welcome. Thanks!

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adafruit_support_bill
 
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Re: 8" eTape Liquid Level Sensor

Post by adafruit_support_bill »

This behavior matches exactly with what I experienced a few days ago when I first tried using this sensor.
So it eventually returned to normal? How long did that take?

From the photo, it looks like you have tape on the front of the sensor. Make sure that it does not obstruct the vent hole.

theherschmeister
 
Posts: 4
Joined: Thu Jul 24, 2014 4:51 pm

Re: 8" eTape Liquid Level Sensor

Post by theherschmeister »

I'd say it's been about a week since I first attempted to use the sensor. However, other than it giving a reasonable resistance when not submerged or even wetted at the very start of both of my attempts to make it work, it has never approached normal functionality.

I can confirm that the tape did not obstruct the vent hole.

Thanks again!

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adafruit_support_bill
 
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Re: 8" eTape Liquid Level Sensor

Post by adafruit_support_bill »

OK. If you contact [email protected] with a link to this thread, we can send you a replacement sensor.

theherschmeister
 
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Re: 8" eTape Liquid Level Sensor

Post by theherschmeister »

Will do. Thank you again for your help!

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