The system is equipped with an internal microprossor to perform all of the needed calculations and to provide signals to the flow controllers. The user only needs to enter the total flow and the concentration of each component gas. Oxymax ER can simultaneously measure 1 to 10 liquid or solid samples, from 50 ml to 10 liter in volume. The patented principle of measurement, which involves air sampling from the head space of the sample chamber, circulating it through the gas analyzer and returning back to the sample chamber without any contact with the sample, assures that the gas analyzer cannot be easily contaminated. Calibration of O 2 gas analyzer is done automatically and periodically with ambient air, removing the need for expensive, precisely-mixed gas bottles while respirometers equipped with the CO 2 analyzer need to be calibrated once a year.
Water vapor is returned to each chamber as water droplets, restoring the sample's moisture content.
The Oxymax ER Respirometer allows either fixed or variable measuring intervals. Fixed intervals may be user set from 3 to 30 minutes. Variable measuring intervals are set by Oxymax ER based on the activity of the sample. In variable mode, the operator sets a gas concentration threshold that, when exceeded, triggers a measurement and a new measuring interval. The Oxymax ER Respirometer has its own microprocessor and can operate without a computer and either print the results on an external printer or send the data to a desktop or laptop computer via an RS-232 interface.