CONDUCTIVITY NOT STABLE DURING LOW CONDUCTIVITY TEST General description of conditions for occurring: Before the conductivity is measured and evaluated the stability is controlled. Technical description of conditions for occurring: * All samples in a continuous 10 sec. long period shall not differ more than ?.4 mS/cm from the average during the same period. * If the test fails it is repeated after 60 sec, but for a maximum of three times. Some possible explanations why the error has occurred:needs to be calibrated. * Conductivity cell B needs to be calibrated. * Conductivity cell is broken. * TPVA valve is leaking. * PBVA valve is leaking.