I want to use an SRF005 inside a water tank so it is going to be very damp. The board is no problem but the transducers must be exposed, does anyone know if the transducers on the SRF005 are moisture proof? I tried replacing the originals with a pair of Jaycar AU5550's on flying leads and while I could get some reaction, if the readings meant anything at all the range was only about 200mm. P.S. I replaced the originals and it works fine.
Moisture proof ulrtasonic rangefinder
- Thread starter Maleny
- Start date
techElder
Well-known member
You'll get corrosion over time, and associated problems with the high voltage that is put on those transducers.
Anything you do to "moisture proof" them will interfere with the transmitted and received ultrasound. Typical underwater transducers are epoxy encapsulated, but the epoxy and stand-off distances are tuned somewhat to the transducer frequency.
Anything you do to "moisture proof" them will interfere with the transmitted and received ultrasound. Typical underwater transducers are epoxy encapsulated, but the epoxy and stand-off distances are tuned somewhat to the transducer frequency.
Similar questions have cropped up a few times here.
http://www.robot-electronics.co.uk/htm/sonar_faq.htm
http://www.robot-electronics.co.uk/htm/sonar_faq.htm
Q. Can we replace the transducers with sealed weatherproof types?
A. No. We have tried these on both the SRF04 and SRF08 and they do not work. The characteristics of the sealed devices requires a different design. Look at the SRF485WPR for a weather resistant part.
I would imagine you'll have similar problems with SRF05.
A. No. We have tried these on both the SRF04 and SRF08 and they do not work. The characteristics of the sealed devices requires a different design. Look at the SRF485WPR for a weather resistant part.
I would imagine you'll have similar problems with SRF05.
1968neil
Senior Member
don't think ultrasonic will be the way to go, hard to achieve reliable results as you've already found.
I built a rainwater harvesting system and i used an MPX2010DP pressure sensor and an LM324 opamp to scale up the output to measure the tank level (1000ltr) and it performs perfectly in my set up. maybe worth a look ?
Regards
Neil
if you want a circuit and a pcb layout i can send them, i added a couple of temperature sensors (DS18B20) for water temperature and the other for atmospheric temp.
I built a rainwater harvesting system and i used an MPX2010DP pressure sensor and an LM324 opamp to scale up the output to measure the tank level (1000ltr) and it performs perfectly in my set up. maybe worth a look ?
Regards
Neil
if you want a circuit and a pcb layout i can send them, i added a couple of temperature sensors (DS18B20) for water temperature and the other for atmospheric temp.
1968neil
Senior Member
Circuit Diagram
Here you go, enjoy.
I have a pcb layout in express pcb format if anyone would like to build one ?
The great thing about using this method is there are no moving parts to jam up etc.
In certain locations this can be a real bonus. I used the tank temperature probe so the system would detect ice to save the pumps from drawing up ice and damaging them.
It has been in use for well over a year now in the UK and i have never had to do anything to it.
Regards
Neil
Here you go, enjoy.
I have a pcb layout in express pcb format if anyone would like to build one ?
The great thing about using this method is there are no moving parts to jam up etc.
In certain locations this can be a real bonus. I used the tank temperature probe so the system would detect ice to save the pumps from drawing up ice and damaging them.
It has been in use for well over a year now in the UK and i have never had to do anything to it.
Regards
Neil
Thanks again Neil
Started looking into MPX2010DP's and couldn't understand how a 10Kpa sensor would do the job. More research took me right back to where I usually start from, Silicon Chip Nov & Dec 2007 plus Jan 2008 have a great series on using an MPX2010DP in a tank gauge project. Can't understand why you need 4 opamps though.
Started looking into MPX2010DP's and couldn't understand how a 10Kpa sensor would do the job. More research took me right back to where I usually start from, Silicon Chip Nov & Dec 2007 plus Jan 2008 have a great series on using an MPX2010DP in a tank gauge project. Can't understand why you need 4 opamps though.
1968neil
Senior Member
The ops amps are to scale up the output to allow adc range and some signal conditioning and impedance matching.
See the link to the application notes i originally used.
Regards
Neil
http://cache.freescale.com/files/sensors/doc/app_note/AN1517.pdf
Peter Goldsbury
Member
have you looked at Maxpbotix ultrasound sensors they have some sealed outdoor ones http://www.maxbotix.com/products/WR.htm