Vapor Generation Accessory VGA–77 Operation manual

VGA–772.2.2 Gas supply requirementsA regulated supply of argon must be provided for your VGA-77through the captive hose located in the right-hand side panel. Youmay also use nitrogen with the AA reagent module only.✒ Note Nitrogen must not be used with the ICP module as it may degrade theperformance of the plasma.The gas supply must comply with the specifications in chapter 1.The VGA is fitted with a 6 mm (1/4") internal diameter reinforcedplastic hose for connection to a standard barbed-tail connector. If youare in any doubt about the correct fittings to use, consult yoursupplier.$POOFDUJOHÁUIFÁHBTÁTVQQMZÁTo connect the gas supply:1. Place the clamp over the free end of the captive hose and connectthe free end of the captive hose to the metalbarbed-tail connector on the gas supply or to your gas supplyregulator.2. Tighten the clamp, by adjusting the screw, to secure the gas supplyhose to the gas supply. Adjust the pressure at the regulator to therecommended pressure.CautionThe argon supply pressure supplied to the VGA-77 must be300 to 400 kPa (43 to 57 psi).✰✰✰ Hot Tip The VGA-77 gas supply may be taken from the main argon gas line toICP spectrometers if you use the following precautions:Insert a suitable ‘T’ piece into the main argon gas supply to divertsome of the gas to the VGA.Attach a regulator to control the flow of argon to the VGA. Place atap in the argon supply to the VGA. The tap is required to shut off theargon supply to the vapor generator, as gas will flow through theVGA-77 even when it is switched off.Within the VGA-77, the inert gas supply is divided into two branches.The first branch is controlled by a solenoid stop valve. It supplies gasto the inlet side of the reaction coil. The second branch supplies inertgas directly through the gas/liquid separator.2-4 Publication date: May 2004