Vapor Generation Accessory VGA–77 Operation manual

VGA–775.1.4 Tubing1VNQÁUVCFTÁWhen the system is not being used, the pressure bar should bereleased, the pump tubes removed from around the rollers andreleased from the retaining bracket. This will minimize distortion ofthe tubes and help to prolong their working life.To reduce mechanical wear of the pump tubes, the outside of the tubesand the surface of the pump rollers should be sprayed daily with asilicone lubricant.If the procedure specified in section 3.4 is followed, the system tubingwill generally remain clean, however the efficiency of all pump tubeswill eventually be degraded to the point at which they must bereplaced. You should regularly monitor the performance of each pumptube using flow rate measurements (see section 3.1.2.). Discard thepump tubes as soon as the results of this monitoring becomeunacceptable.✒ Note The tubes connecting the black-black pump tubes to the pump modulemay occasionally need to be replaced. To do this, cut four 2 cmlengths of the thinner black Viton tubing supplied. Place these overeach end of two of the black-black pump tubes.'MVPSPFMBTUPNFSÁUVCJOHÁThe fluoro-elastomer tubing connecting the gas/liquid separator to theabsorption cell is particularly susceptible to contamination withpotassium iodide. To avoid this, it is recommended that you dedicate aseparate module to the analysis of those elements requiring prereductionwith KI (i.e. As or Sb).The cleaning procedure for the fluoro-elastomer tubing is as follows:If there is no KI contamination, you can clean the tubing by flushingit well with distilled water.If there is KI contamination, you need to remove traces of KI asfollows:1. Disconnect and remove the tubing.2. Soak the tubes in sodium hydroxide solution (0.5% w/v). Washthoroughly with dilute hydrochloric acid and then washthoroughly with distilled water.3. Allow the tubes to air dry in a dust-free location.4. Reconnect the tubing.5-4 Publication date: May 2004