If your model results are different than your field results, I agree with ladyce to check that you have input all information correctly. Another possibility may be there are valves that are closed in the field that are not reflected in your model. You may want to ask the maintenance staff to...
Can you provide a bit more information? What size sewer line will you be measuring from? Is this a temporary measurement or do you need continuous flow measurement?
Keiki
I work for a wastewater utility in California. Our construction standards require the use of VCP for all sanitary sewer installations under 36" diameter. This standard was set as we were concerned with the potential for degredation of plastic pipe should certain chemicals be discharged into...