Ultrasonic Water Level Sensor design

[MakJ]

Hi everyone,

I want to custom design an ultrasonic water level sensor using a combination of sparkfun board:
https://www.sparkfun.com/products/13959

and integrated Transducer (Rx/Tx) in sealed package sourced from jaycar:
https://www.jaycar.com.au/ultrasonic-transducer-transmitter-receiver/p/AU5550

The measurement range (one way) is upto 6m max.
An integrated sealed transducer best suit the requirement as the sensor might get wet during flooding or overflow conditions.

1. I reversed the schematic for sparkfun board (attached). Has someone done the same and verify if I got the connections right?

2. For sealed transducer at an extended range than rated on board, I am thinking of adding 9V driven amplifier stage. Should the higher voltage suffice to operate the sealed unit or do I really need to purchase MOSFET drivers (like TC4420)? I will have to tristate the bus eventually when receiving from same sensor.

3. How can I test if the receiver stage of sparkfun board work with integrated transducers RX circuits?

What I really want is to be able to run a sealed transducer with a simple send/receive circuit using the sparkfun board.

Please guide.

 

[kellys_eye]

You will need matched transmit/receive sensors to detect range.

Can you get the datasheet for the individual transducers?

 

[MakJ]

Is there a meter I can use to measure tx signals coming out of a transducer?
Both the pair versions on sparkfun board and the single transducer AU5550 are tuned for 40kHz operation.
Do I need to drive it with higher voltage than 0-5V for 6m range? As discussed here:
https://www.electronicspoint.com/threads/ultrasonic-range-meter.9431/

 

[Alec_t]

Is there a meter I can use to measure tx signals coming out of a transducer?

An oscilloscope.

 

[MakJ]

An oscilloscope.

Are you suggesting I measure 40kHz ultrasonic signal coming out from a transducer using an oscilloscope?

 

[Alec_t]

Yes. Perfectly possible for a receiving transducer and if 'tx' is interpreted as 'having been transmitted'. If, on the other hand, you are referring to the emitted acoustic signal, then perhaps a 'bat detector' could be used to monitor that.

 

[kellys_eye]

You can either 'up' the transmit power or increase the sensitivity of the receiver.

But since the linked-to devices have a working range of up to 6m, you're looking at a rather large tank if you can't measure water content at that range even with the closed-top version fitted. In lieu of the specific data sheets, best you actually trial the closed-top version in place of the open before committing to adapting circuitry that may not be necessary.