Filters
There are two filters that are intended to prevent soot or other contaminants from entering the unit. The first is a light-blue colored in-line filter that is located at the end of the sample tubing assembly. The second is a bowl filter located on the inside of the lid. Periodic inspection of these filters will ensure smooth operation. When new, the elements in both of these filters are a yellow/white color. Both are oriented in the sample stream in a manner that causes any contaminants to collect on the outside of the filter media, which allows for a visual inspection of filter status. If the primary filter is properly maintained, the secondary filter will rarely require changing.