Sensor Help - please

[KevinR]

I am looking for a sensor to measure the water temperature in a tank that can be connected via my RFXcom.

Looking at many sensors on the web I find that they are room/external/weather sensors without a waterproof probe to go into a tank.

Has anyone got a working example or can recommend a sensor?

My setup uses:

A dedicated Intel PC, running Windows 10
Domoticz ver: 3.4834 2016-03-02
RFXtrx433E
Transceiver type = 433.92MHz
Firmware version = 1002
Firmware Type = Ext2
Transmit power = 10dBm
Hardware version = 1.3

Any help would be appreciated.
Regards
Kevin R

[[email protected]]

If you can find a unit with an external sensor probe, then in principle it should be possible to make the probe water-proof (if you really need to immerse it directly?). Some sensors will use a thermistor bead - these can be purchased readily (Farnell in the UK, a typical standard unit gives 10kOhms at 25 Centigrade). Other sensors may use digital thermometers such as DS18B20 (also available from Farnell). A small amount of re-wiring will make either type waterproof. Construction will vary depending upon how rapidly you need the sensor to respond. You can seal the sensor wires with epoxy resin or with silicone - in which case i strongly recommend FERNOX LS-X sealer.

You don't specify what sort of "tank" you have and whether or not you expect rapid temperature changes. Can you bond a sensor onto the outer surface with a little insulation behind it to isolate from the atmosphere? Does your tank have an existing probe sleeve fro a boiler sensor or for an immersion-heater sensor? If so, you could place your new probe into one of these sleeves. In my case I used a FIBARO universal sensor PCB and the DS18B20 placed next to the boiler thermostat. I appreciate that this is Z-WAVE and not 433 MHz RFlink - I only try to give you an example.

Good luck!

[KevinR]

Hi Tony, Thanks for the reply, really useful.

The sensor is to monitor the temperature of my Marine Fisk Tank (Coral Reef) and to provide alarms/notifications when the parameters get too high/low.

I have a z-stick and have today ordered the FIBARO universal temp module and the DS18B20 Waterproof Digital Temperature Probe.

Wish me luck - I'll keep you posted on how it goes.

Thanks again.

Kevin R

[[email protected]]

I wish you luck with this project!

One tip: the universal sensor can accept several sensors, wired in parallel (possibly using shielded twisted pair cable). You should include the universal sensor in your network only AFTER you have connected the desired (or final) number of thermometers to it. If you attempt to connect an extra thermometer later on, then you have to exclude and then re-include the universal sensor before the new thermometer can be recognised. You might wish to add one more sensor to measure room temperature.

Also, note that you have the ability to sense two switch-contacts with this module.

You will need a power supply!

TC

[Derik]

dear...
i cannot see your setup..
Only by a cheap esp8266
bij some dallas waterproof tempsensors with 2 or 3M cable.
By a wterproof case. all in China
And a 5V powersupply

Setup espeasy
place 1 to 10 dallassensors.
place the esp near the tank in a dry place...
esp needs only Wifi...???
and when you use a ir distance sensor you can monitor the tank for full and empty..
And perhaps you will now more sensoren/ switches
Lights on an of.. possible with al nice china stuff

Think this setup will cost you max $30
And you have the best sensor....

questions???

Love Domoticz with Esp....