ElectronicsNut

Interesting, and it is probably due to the lack of supplies, but there are a lot less thin film pressure sensors out there now. I have not looked for any in the last few years, but I did find a 100kg version. Unfortunately, it is not on Amazon but some other site which I have never heard of. Not even sure if the 100kg version is enough for your tank even though the entire weight of the tank will not be on that specific point.

Well here is the site anyway. Good luck

""https://www.tindie.com/products/ICStation/100kg-thin-film-pressure-sensor-for-arduino11690/""

@electronicsnut That's interesting but I think it's not suitable and here is my rationale.

I always assume any measuring device is inaccurate at the extremes so I would think a 100Kg unit is good to 80Kg. My tank contents  are 185Kg if pure water. Who know how much for sewage. That means the sensor is maxed out at between 43% and 54% of tank capacity (likely a fair amount less due to NON pure water). Since the empty tank has a weight and I see no way to TARE that, it is part of the Max 100Kg.

For a black tank, the most important measurement zone is between 80% and 100%. I don't care if it's wildly innacurate at 10% whereas with fresh water it is the reverse, most important approahing zero, don't care at 100%.

Now if there was one of those devices that had a temperature compensated maximum of 250Kg then that would be useful. I searched that site and didn't find any.

@electronicsnut I think that is the same sort of sensor being discussed in another thread about measuring long bow pull weight. 

@zander you may think about adding 4 or more of these sensors to the side of you tank(s) and connecting them to an Arduino or Pi. Afix them at 1/4, 1/2.... They cost about $15USD each, which is not to bad. Not sure how they would react to a crappy or soap film on the back side of the tank wall. May not have any effect on these sensors.

""  https://www.amazon.com/dp/B07FC5RGC7/?coliid=I3ANBSPG6XKPM7&colid=F2RW9EUFC692&psc=1&ref_=lv_ov_lig_dp_it 
""

Have a GREAT DAY,

Don

@electronicsnut Can you put the link in a quote block wrapped in double quotes, This forum does not like amazon links.

@electronicsnut 

Please rewrap the Amazon URL as "the URL here" instead of ""the URL here""

Now the last 2 posts were a little on the confusing side for me, so here are both ways. Not sure as to what went wrong in my post above. Sorry

"https://www.amazon.com/Taidacent-Contact-Liquid-Sensor-Controller/dp/B07FC5RGC7/ref=pd_lutyp_ci_mcx_mr_typ_d_sccl_1_1/135-4552756-2216654?pd_rd_w=ZRFov&pf_rd_p=f6afbe6e-f56a-4b64-9493-07a01722d421&pf_rd_r=53422TY1FTR2TAEZXCH0&pd_rd_r=eba39190-2bfe-4d14-b757-709296a21ad7&pd_rd_wg=AU8Sg&pd_rd_i=B07FC5RGC7&psc=1"

""https://www.amazon.com/Taidacent-Contact-Liquid-Sensor-Controller/dp/B07FC5RGC7/ref=pd_lutyp_ci_mcx_mr_typ_d_sccl_1_1/135-4552756-2216654?pd_rd_w=ZRFov&pf_rd_p=f6afbe6e-f56a-4b64-9493-07a01722d421&pf_rd_r=53422TY1FTR2TAEZXCH0&pd_rd_r=eba39190-2bfe-4d14-b757-709296a21ad7&pd_rd_wg=AU8Sg&pd_rd_i=B07FC5RGC7&psc=1""

@electronicsnut 

It's not your fault, the forum has a poltergeist 🙂

For some reason, the forum seems to choke on most of the URLs referencing Amazon. It displays the picture but when you click on it, it doesn't follow back to the source, it just displays a message saying the Kindle can't access the page. So, we usually wrap the URL in quotes to prevent the forum from expanding it.

@electronicsnut Not sure if/how that would work, but at $20 a unit I can try one, not sure about the circuit I need to build, looks like some study on my part is needed.

For LP tanks I believe one needs to be a little creative. After much research it looks like the best measurement is by weight. Below is a picture of a scale in progress. If I remember correctly I still need to compensate for temperature. I made 2 sets of these since I have (2) 30 pound tanks.

@electronicsnut I use the Mopeka sensor, I think it's ultasonic. Can't use weight when the tanks are securley strapped in position.

Posted by: @electronicsnut

Now the last 2 posts were a little on the confusing side for me, so here are both ways. Not sure as to what went wrong in my post above. Sorry

"https://www.amazon.com/Taidacent-Contact-Liquid-Sensor-Controller/dp/B07FC5RGC7/ref=pd_lutyp_ci_mcx_mr_typ_d_sccl_1_1/135-4552756-2216654?pd_rd_w=ZRFov&pf_rd_p=f6afbe6e-f56a-4b64-9493-07a01722d421&pf_rd_r=53422TY1FTR2TAEZXCH0&pd_rd_r=eba39190-2bfe-4d14-b757-709296a21ad7&pd_rd_wg=AU8Sg&pd_rd_i=B07FC5RGC7&psc=1"

""https://www.amazon.com/Taidacent-Contact-Liquid-Sensor-Controller/dp/B07FC5RGC7/ref=pd_lutyp_ci_mcx_mr_typ_d_sccl_1_1/135-4552756-2216654?pd_rd_w=ZRFov&pf_rd_p=f6afbe6e-f56a-4b64-9493-07a01722d421&pf_rd_r=53422TY1FTR2TAEZXCH0&pd_rd_r=eba39190-2bfe-4d14-b757-709296a21ad7&pd_rd_wg=AU8Sg&pd_rd_i=B07FC5RGC7&psc=1""

 

Alternatively:

Contactless Water Tank Water Level Sensor

Make a shorter URL

@frogandtoad 

Alternatively:

Contactless Water Tank Water Level Sensor

Make a shorter URL

Haven't seen that one before.

Also for Amazon links there is a way to de-countrify it. What I mean is I am in Canada so my amzon links have a domain of .ca but amazon has a way to create a link that will automatically change my .ca to whatever is closest to you. That's all I know about it.

EDIT Forget about it, it's only for amazon associates and you need accounts in each country (not the same as what I have now with simply changing the .ca)

@zander

Posted by: @zander

@frogandtoad 

Alternatively:

Contactless Water Tank Water Level Sensor

Make a shorter URL

Haven't seen that one before.

Also for Amazon links there is a way to de-countrify it. What I mean is I am in Canada so my amzon links have a domain of .ca but amazon has a way to create a link that will automatically change my .ca to whatever is closest to you. That's all I know about it.

 

Such "make shorter link" websites have been around as long as I can remember the internet being available... they just help to simplify (shorten) URL's by simply mapping a shorter one to the specified target, and re-directing you there - This helps to bypass any amazon link anomalies going on, allowing us to simply paste in a normal link.

@frogandtoad I have tried a few over the years and stikl have a bitly account but never seemed to have any luck using them. Next time I have an amazon link to post I will try again. Thanks for the reminder.

EDIT I just discovered I have a amazon url shortner on my browser toolbar. Now to remember to use it.