Select element to be tested in drop down – NH3, NO2, NOx, O3 or SO2. RTI Lab analysis with results are emailed to user. Results are emailed to user. RTI Lab to wash and load sampler, etc. Pre-coated pads supplied by user. RTI Laboratories is a leading provider of environmental testing services. Analyses are performed under the guidance of various regulatory programs utilizing published and in-house developed and validated methods.