IS 13109 : Part 4 : 1991 Specification for electronic equipment/systems for use in coal and metaliferrous mines:Part 4 Requirements for sound powered magneto telephone systems

1 Scope

1.1 This standard covers the requirements for sound poweredmagneto telephone systems for use in coal and metalliferrous mines.

1.2 This standard shall be read in conjunction with IS 13109 :Part 1 : 1991.

2 Reference

IS 13109 : Part 1 :1991 Specification for ElectronicEquipment/Systemsfor use in coal and metalliferrous mines:Part 1 Definition, General Requirements andTests