Did you know you can test the accuracy of your equipment before you get on site? As a manufacturer, we often get tech support calls from auditors who are on site, and wondering if their equipment is providing an accurate reading. Thankfully, there is an easy way to test both your duct tester and gauge, regardless of manufacturer, before you get on site. There is, after all, nothing worse than showing up on site, and not being confident the equipment is working properly.
For your gauge or manometer, perform a simple "Field check of tubing and digital gauges". This calibration check can be completed before an important test, checking gauge accuracy to ensure it remains within original specifications. A simple procedure of connecting both channels of the manometer to each other will allow you to verify your equipment accuracy, and check the tubing for leakage and blockage because they are also a major source of testing errors.
For the duct testing fan, you can test the accuracy with a field calibration plate - a simple 5 minute check to verify the equipment. You should check your duct tester accuracy in both directions, pressurization and depressurization, and then compare with manufacturer specifications. Ideally, your fan should provide equally accurate results in both directions. Ask your equipment manufacturer for a field calibration plate, although you can test any fan on any calibration place, or you can make your own! All you need is a plate with a hole of a known size. For instructions and the full procedure go to: http://www.retrotec.com/residential/Articles.aspx.