| changed using the ↑ and ↓ arrow keys. During calibration, the |
| "%" sign will flash at a once per second rate. When the |
| calibration value is set, pressing the CALIBRATE or |
| LOCK/UNLOCK key will cause the unit to exit the calibration |
| mode and return to normal operation. The unit will also revert to |
| normal operation if 10 seconds elapse and no keys are pressed. |
7 | ↑ and ↓ Keys- The ↑ and ↓ arrow keys are used in |
| conjunction with the CALIBRATE key to calibrate the |
| unit. Pressing the ↑ or ↓ key will raise or lower the displayed |
| oxygen value in .1% increments. When either of these keys are |
| held down for more than 1 second, the display will scroll at a rate |
C | of .4% per second. |
Sample Inlet Connection |
1.3MAX-250 Oxygen Sensor
MAX-250 oxygen sensors offer quick response, stability and extra life on the order of 900,000 percent oxygen hours.
The MAX-250 is a galvanic, partial pressure sensor that is specific to oxygen. It consists of two electrodes (a cathode and an anode), a teflon membrane and an electrolyte. Oxygen diffuses through the teflon membrane and immediately reacts at a gold cathode. Concurrently, oxidation occurs electrochemically at the lead anode, generating an electrical current and providing a voltage output. Electrodes are immersed in a unique gelled weak acid electrolyte which is responsible for the sensors long life and motion insensitive characteristic. Since the sensor is specific to oxygen, the current generated is proportional to the amount of oxygen present in the sample gas. When no oxygen is present, there is no electrochemical reaction and therefore, negligible current is produced. In this sense, the sensor is self-zeroing.
CAUTION: The Maxtec MAX-250 oxygen sensor is a sealed device containing a mild acid electrolyte, lead (Pb), and lead acetate. Lead and lead acetate are hazardous waste constituents and should be disposed of properly, or returned to Maxtec for proper disposal or recovery.
CAUTION: Do not use ethylene oxide sterilization. Do not immerse the sensor in any cleaning solution, autoclave or expose the sensor to high temperatures.
CAUTION: Dropping or severely jarring the sensor after calibration may shift the calibration point enough to require recalibration.