CEMSS & Mars Garden Sensor Web The base unit for data acquisition is the Vernier Software LabPro® (right). It offers unparalleled flexibility, power, portability, and ease of use at an affordable price. The LabPro interfaces with a computer, via either USB of Serial. The LabPro is also portable, with the ability to take data without a computer. Sensors are automatically recognized and calibration is handled for you. We will be employing the LabPro with Vernier's CO2 and O2 gas sensors, Relative Humidity, pH and temperature probes. Additional temperature readings will be acquired with an Onset Hobo® four-channel temperature acquisition system, (left). Data recording for the Vernier and other devices will be relatively automatic, initially being stored within the devices for later download to a computer. An additional Vernier Digital Control Unit will be included, which will allow for the programming of the sensors via Visual Basic to control various operations of the CEMSS, such as automatic control of the HVAC system in relation to changing temperature conditions.