巴西采购需求：电动割草机、漏水检测器、二氧化碳传感器、自动割草机、智能气象站、自动割草机

I'm with GMAPRO INDUSTRIAL in Brazil, and we're working on our online monitoring platform, COIOT.AI. We're looking for oxygen level measurement sensors for testing in a Proof of Concept (POC). If all goes well, we'll be needing around 7000 sensors to start. The setup requires measuring O2 in a box, preferably with a mobile sensor at the end of a flexible tube. The operating environment conditions are 22°C, 60% humidity, and 1 atm pressure, with a natural O2 level of 21%. We're interested in measuring O2 levels between 0-30%. It's essential that the sensors can send data to our platform via MQTT. If MQTT isn't an option, we would consider alternatives in the following priority: LoRaWAN and Modbus RS485. Looking forward to your suggestions!