Improvement from microlaterolog/ML instrument to MSFL/ML instrument

In view of the problem that the newly-improved MSFL/ML instrument can not match the 3506XA PCM instrument in combination logging, this paper makes a deep analysis and discussion and brings forward a new way to improve the electronic circuit of 3506XA PCM. The newly - improved 3506XA PCM instrument can meet the requirements of combination logging. The application in hundreds of wells shows it is in stable condition while working.