The Bacharach 0021-0018 replacement smoke scale is used with the Bacharach True Spot smoke test kit (sold separately). The comparison scale is used to determine oil burner smoke readings. The test method meets Installation Standards of the National Oil Fuel Institute by U.S. Department of Commerce, Testing materials (D2156-65), and German Standard DIN 51-402.
Bacharach manufactures instruments for the measurement and detection of gases and liquids, including combustion analyzers, fixed gas monitors, and leak detectors for the HVAC industry. The company, founded in 1909, is headquartered in New Kensington, PA.