Method 4 : Determination of Moisture Content in Stack Gases
In this method, a gas sample is extracted at a constant rate from the source; moisture is removed from the sample stream and determined either volumetrically or gravimetrically.
The method contains two possible procedures: a reference method and an approximation method.
The required equipment is shown in the table below.
| Type of sampling → Equipment ↓ |
Reference Method | Approximation Method |
| Probe | Stainless steel or glass tubing, sufficiently heated to prevent water condensation, and equipped with a filter, either in-stack or heated out-of-stack to remove particulate matter. | |
| Condenser | As required in Method 5 | Two midget impingers, each with 30-ml capacity, or equivalent. |
| Cooling Systems | An ice bath container, crushed ice, and water (or equivalent), to aid in condensing moisture. | |
| Drying Tube | - | Tube packed with new or regenerated 6- to 16-mesh indicating-type silica gel (or equivalent desiccant), to dry the sample gas and to protect the meter and pump. |
| Pump | - | Leak-free, diaphragm type, or equivalent, to pull the gas sample through the train. |
| Volume Meter | - | Dry gas meter, sufficiently accurate to measure the sample volume to within 2 percent, and calibrated over the range of flow rates and conditions actually encountered during sampling. |
| Flow rate Meter | - | To measure the flow range from 0 to 3 liters/min |
| Vacuum Gauge | - | to be used for the sampling leak check. |
| Flow rate Meter | - | To measure the flow range from 0 to 3 liters/min |
| Barometer | - | - |
| Graduated Cylinder | - | - |
We manufacture and / or supply all equipment required for implementation of Method 4 and much more.