Their sensitivity to humidity, heat and low oxygen environments can cause drift and cell deterioration.[2] Other interferences include methyl and ethyl mercaptan, SO2, phosphine (PH3), NO2 and other light hydrocarbons.[11] Lead Acetate Tape Gas Detectors have been around for Decades but are Susceptible to a Number of Interferences Lead acetate tape gas detectors have been in use for the past several years and still play a key role in various industries. They are widely used for fixed-point H2S monitoring and to monitor scrubber efficiency. The color of the lead acetate tape changes when H2S is present.[1] The instrument is equipped with specially calibrated optics to measure H2S concentration by determining slight variations in the depth of the color change. Lead Acetate Detection Strips Circa 1914 [17] This kind of analyzer is primarily stationary, but some portable options are also available. The lead acetate tape is prone to interference from low and high humidity and SO2.[13] Dry conditions can cause the analyzer to underreport results, whereas high humidity can cause the glass components to fog and the tape to become moist (humid conditions).[13] These conditions can distort the color as it perceived by the optic system, thus skewing the final test results. Lead acetate cassette tape gas detectors are highly expensive, especially due to the necessity to replace cassettes frequently - every 1 to 4 weeks or longer depending on the frequency of sampling, amount of tape on the roll and the environment wherein the sampling is carried out. Since lead acetate cassette tape gas detectors have a set shelf life, it is necessary to store them carefully to avoid any potential damage caused by factors such as ambient humidity. Metal oxide semiconductors (MOS), sulfur titrators, flame photometric detectors (FPDs), sulfur chemiluminescence and field olfactometers are all useful technologies/methods for H2S detection. However, they are not described in detail in this article due to various reasons, including subjectivity of results, complicated testing procedures, special training required, lack of portability, slow response time or an inability to determine individual sulfur compounds.[1][2] Choosing the Correct H2S Analysis Technology is Essential Although different types of methods are available for H2S detection, no single method can be considered to be the ideal technology for all situations, but some methods have clear advantages over other methods. The EPA recommended method is SO2 conversion, but this method is only available as a stationary analyzer.

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