Battery types in blasting galvanometers

October 12, 1977

Mr. Howard Lawrence President
E.I.T. Corporation
[Recipient address omitted]
Dear Mr. Lawrence:

This is in response to your letter of September 21, 1977, addressed to Mr. David W. Hadden, regarding the use of carbon zinc batteries in blasting galvanometers.

29 CFR 1926.906(q) in construction standards states:

Blasters, when testing circuits to charged holes, shall use only blasting galvanometers equipped with a silver chloride call especially designed for this purpose.

29 CFR 1910.109(e)(4)(vii) in general industry standards states:

Blasters, when testing circuits to charged holes, shall use only blasting galvanometers designed for this purpose.

The Occupational Safety and Health Administration (OSHA) enforces the aforementioned standards as written. To answer your specific question, there are two parts.

First, OSHA construction standards prohibit the use of all batteries, except a silver chloride cell designed for the purpose, in blasting galvanometers.

Second, OSHA general industry standards permit the use of any type battery in blasting galvanometers, if the blasting galvanometer, including the energy source, is designed for the purpose.

The Office of Standards has your comments, as well as other interested parties' comments, for consideration in reviewing standards covering the type instruments and power sources the blaster uses in testing circuits to charge holes.

If I may be of any further assistance please feel free to contact me.

Sincerely,
John K. Barto, Chief
Division of Occupational Safety Programming