"This recommended practice applies to all toxic gas detection instruments that satisfy the performance requirements in ISA-S92.0.01@ Part I. Refer to Clause 3 of ANSI/ISA-S92.0.01@ Part I@ for definitions of terms as used herein. References useful in the installation@ operation@ and maintenance of toxic gas detection instruments are listed in Annex C. These references are not considered to be part of this document except for those specific sections of documents referenced elsewhere in this Recommended Practice. Purpose ISA-RP92.0.02@ Part II@ establishes user criteria for the installation@ operation@ and maintenance of toxic gas detection instruments. Its companion standard@ ISA-S92.0.01@ Part I@ ""Performance Requirements for Toxic Gas Detection Instruments@"" has been prepared to provide minimum requirements for the performance of toxic gas detection instruments."