Hi guys

I am doing small project for my farm (Green House) using Siemens LOGO! 8 so I am looking compatible sensors for it 

PH Sensor

Range 0-14.0 pH ± 0.5 pH

EC Sensor (or TDS Sensor)

Range 0 - 5 EC ±  0.1 EC

or

Range 0 - 2500 TDS ± 50 TDS

Temperature Sensor

(to measure the air temperature inside the green house)

Range 0 - 50 C± 2 C

Humidity Sensor

(to measure the air humidity inside the green house)

Range 20 - 75%  ± 5%

Could you please support me in how to select the right product with affordable price

Hi,

 I think people here won't help with selection of sensors. You need to find the right one based on quality and then you can compare the price of quality stuffs. There are affordable sensors, then at the end it comes about reliabilty.

 Mostly people here don't deal with sensors.

Hi,

For a combined temperature and RH sensor - see attached which is suitable for your application. QFA31xx with the AQF3100 radiation shield. You have 0-10VDC and 4-20mA signal options. 

Regards,