Perform annual factory calibration and preventative maintenance on Landtec GEM 5000 Plus Portable Gas Analyzers against LandTech/QED Environmental Systems equipment or equivalent. This calibration and assessment process shall include the following: 1. Instrument Inspection 2. Instrument Calibration: • Methane: 0-100% (volume) • Carbon Dioxide: 0-100% (volume) • Oxygen: 0-25% (volume) • Carbon Monoxide: 0-2000 parts per million • Hydrogen Sulfide: 0-1000 parts per million • Atmospheric pressure, differential pressure and calculates gas flow 3. Oxygen cell programming (as needed) 4. Firmware Updates (as needed) 5. Replacement of sensors, transducers, pump, keypad, lens, tubing, USB cable, battery, shipping box (as needed) 6. Return freight 7. All equipment must be calibrated according to manufacturer’s protocols using traceable equipment that meets manufacturer’s calibration specifications. 8. A unique and signed Statement of Calibration must accompany each newly calibrated Landtec GEM 5000 Plus instrument. 9. If during the inspection of the instrument a mechanical problem is discovered that would affect its ability to pass the calibration process, a written quotation will be provided to the customer prior to servicing the instrument.