LuminOx oxygen sensor

Hello all, new forum user here.

I am trying to get a LuminOx optical oxygen sensor, found, with data sheet at:

http://www.sstsensing.com/Products/Gas-Sensors/Oxygen-Sensors/LuminOx-Optical-Oxygen-Sensor/188

To give data to my Arduino Uno. The data sheet says that the sensor responds to RS232 commands, but the Arduino uses TTL? I have no idea where to start, in both sending commands to this sensor, and receiving the data. It maybe important to note that the final intention is not to interact with the sensor via a serial link to a computer, as the end system needs to be free standing. I have researched max chips that may be able to help, but having never really attempted anything in this field before I would really appreciate any basic advice or ideas of how this might be achieved. (also I have an ethernet shield to store the data to a micro SD if that is important in anyway)

Thanks in advance

You can use the 5V pin of the Arduino to power the sensor.
The term "3.3V TTL level RS232" indicates that the serial connection is with digital signals of 3.3V.
The Arduino Uno uses 5V digital signals, so you have to adapt them to 3.3V.

The conversion of RS232 5V to 3.3V is not hard to do, I can't find it right now. Hopefully someone else knows.

The serial port is used to upload a sketch and for the serial monitor.
But if you use SoftwareSerial, you can create a second serial port for the sensor.

That way, you can still send messages to the computer, and have full control over the sensor.

Here is arduino example for COZIR co2 sensor. I think there is something same as LuminOx optical oxygen sensor.
http://www.co2meters.com/Documentation/AppNotes/AN128-%20Cozir_Arduino.pdf