GC DETECTORS Reduction Gas Detector - RGD The SRI Reduction Gas Detector is the most sensitive detector available for hydrogen, carbon monoxide, and other reducing gases. Low ppb detection limits are achievable for hydrogen. Detection limits in the ppt range are achievable for carbon monoxide. 10-port gas sampling valve in heated oven The RGD comes with a 10-port gas sampling valve and 1mL sample loop for inj ecting samples. Exit tube The RGD exit tube is not factory equipped with a mercury vapor filter, since it was designed for trace detection. Depending on the concentration of the reducing gases in the sample, you may want to add a filter for safety. The amount of mercury vapor produced is proportional to the concentration of reducing gases in the sample.

GC DETECTORS Reduction Gas Detector - RGD Theory of Operation The SRI RGD detector uses a mercuric oxide (HgO) reaction tube and a mercury lamp in a heated UV detector cell. The reaction tube is heated to 260-300oC. Located immediately downstream of the reaction tube, the UV detector cell is heated to 170oC. The UV detector cell is equipped with a mercury lamp and a UV photodiode. When a reducing gas such as carbon monoxide elutes from the GC column, it reacts with the HgO to form gaseous mercury vapor, which is then swept into the UV cell. The gaseous mercury absorbs the UV light from the mercury...

GC DETECTORS Reduction Gas Detector - RGD Expected Performance 50ppb Sample: 100mLs room air in 1000mL tedlar bag = 50ppb The following two chromatograms were produced with an SRI RGD equipped GC. Room air samples were diluted with nitrogen in tedlar bags, then injected by gas sampling valve onto the Molecular Sieve packed column. Results: Component Ret.Time Area HYDROGEN 2.433 100.8250 OXYGEN 3.500 796.4090 Common Analytical Parameters: Valve injection; 1mL sample loop Column: 2-meter Molecular Sieve 13X Carrier: helium at 5mLs/minute RGD gain: HIGH Reactor temperature: 290oC Detector temperature:...

GC DETECTORS Reduction Gas Detector - RGD General Operating Procedure 1. When your RGD GC arrives, the photo diode amplifier leads will have been disconnected for transport. Locate the insulated electrical lead with two protruding wires: 1 black, 1 yellow. These wires plug into the back end of the RGD assembly, where the photo diode is located. The black is the ground wire; plug it onto the upper prong. Plug the yellow wire onto the lower prong. photo diode amplifier leads yellow black 2. Turn ON the main GC power (the switch is located on the left-hand side of the GC). 3. Connect helium or nitrogen...

GC DETECTORS Reduction Gas Detector - RGD Maintenance Reaction Tube Packing and Replacement SRI provides you with one replacement reactor tube in your accessories kit. However, you may also remove the mercuric oxide (HgO) and re-pack the reactor tube, for which you will need fresh HgO and quartz wool. HgO powder is available from Sigma-Aldrich: part #203793-2G: www.sigmaaldrich.com, or call: 1-800325-5832. Quartz wool is available from Restek: catalog #20999: www.restekcorp.com, or call 1-800-3561688. To remove the reactor tube, loosen the fitting that secures it to the column and RGD jet, and...