My apologies if this question is a repeat. I sent it once but did not see it posted or see any response so I am trying again. I have run across an internal specification which applies an equivalency factor to the maximum allowable limit for an Omegameter 300 and an Omegameter 600 - but NOT to the maximum allowable limit for an Omegameter 500. In other words, the maximum permissible micrograms NaCl eq./sq.cm. for the Omegameter 500 is less than that for the Omegameter 300 and Omegameter 600. Can anyone explain the logic for this? Is the Omegameter 500 different? Thanks in advance for your help. Mary M. Davis Eldec 425-743-8327 ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################