A mercury monitoring system comprising: - a probe configured to retrieve a gas sample from a gas source and coupled to a gas supply that provides a dilution gas to the probe to reduce a relative concentration of mercury within the gas sample; - a heated conduit configured to limit condensation of the gas sample; - an oxidized mercury converter coupled to the probe by the heated conduit , the oxidized mercury converter comprising: - a heater configured to heat the gas sample admitted into a chamber so as to convert oxidized mercury present within the gas sample into an elemental mercury component and an oxidizing component; - a mercury analyzer comprising, - a housing ; and - a fluorescence assembly ; wherein the housing has an inlet , and an outlet , and defines a chamber configured to contain a gas sample during analysis of the gas sample ; wherein the fluorescence assembly includes a light source assembly and a detector assembly in optical communication with the chamber , and wherein the fluorescence assembly is arranged for inducing fluorescence of elemental mercury present within the gas sample and for detecting a fluorescence signal of the gas sample based upon fluorescence of the elemental mercury , respectively; wherein the mercury analyzer further includes a fluorescence quenching reduction apparatus coupled to the housing , and that is arranged for reducing the pressure of the gas sample relative to that of a fluid source; and a calibrator connected to the converter configured to provide a known concentration of elemental mercury and oxidized mercury to the converter . - a probe configured to retrieve a gas sample from a gas source and coupled to a gas supply that provides a dilution gas to the probe to reduce a relative concentration of mercury within the gas sample; - a heated conduit configured to limit condensation of the gas sample; - an oxidized mercury converter coupled to the probe by the heated conduit , the oxidized mercury converter comprising: - a heater configured to heat the gas sample admitted into a chamber so as to convert oxidized mercury present within the gas sample into an elemental mercury component and an oxidizing component; - a heater configured to heat the gas sample admitted into a chamber so as to convert oxidized mercury present within the gas sample into an elemental mercury component and an oxidizing component; - a mercury analyzer comprising, - a housing ; and - a fluorescence assembly ; - a housing ; and - a fluorescence assembly ; wherein the housing has an inlet , and an outlet , and defines a chamber configured to contain a gas sample during analysis of the gas sample ; wherein the fluorescence assembly includes a light source assembly and a detector assembly in optical communication with the chamber , and wherein the fluorescence assembly is arranged for inducing fluorescence of elemental mercury present within the gas sample and for detecting a fluorescence signal of the gas sample based upon fluorescence of the elemental mercury , respectively; wherein the mercury analyzer further includes a fluorescence quenching reduction apparatus coupled to the housing , and that is arranged for reducing the pressure of the gas sample relative to that of a fluid source; and a calibrator connected to the converter configured to provide a known concentration of elemental mercury and oxidized mercury to the converter . <EOS>