Search results
Results from the WOW.Com Content Network
According to ISO 764 or its equivalent DIN 8309 (Deutsches Institut für Normung - German Institute for Standardization) a watch must resist exposure to a direct current magnetic field of 4800 A/m. The watch must keep its accuracy to ±30 seconds/day as measured before the test in order to be acknowledged as a magnetic-resistant watch.
One difference between the Gaussian and SI systems is in the factor 4π in various formulas that relate the quantities that they define. With SI electromagnetic units, called rationalized, [3] [4] Maxwell's equations have no explicit factors of 4π in the formulae, whereas the inverse-square force laws – Coulomb's law and the Biot–Savart law – do have a factor of 4π attached to the r 2.
The criterion of resistance to magnetic fields is innovative. Until now, the ISO 764 Horology — Magnetic resistant watches standard defines that an antimagnetic watch must support a magnetic field of 4,800 A/m, which corresponds to 60 gauss. METAS certification subjects watches and movements to 15,000 gauss (1.5 tesla).
In the CGS system, the unit of the H-field is the oersted and the unit of the B-field is the gauss. In the SI system, the unit ampere per meter (A/m), which is equivalent to newton per weber, is used for the H-field and the unit of tesla is used for the B-field. [3]
The conversion factor is 10 8 maxwell per weber, since flux is the integral of field over an area, area having the units of the square of distance, thus 10 4 G/T (magnetic field conversion factor) times the square of 10 2 cm/m (linear distance conversion factor). 10 8 Mx/Wb = 10 4 G/T × (10 2 cm/m) 2.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In physics, natural unit systems are measurement systems for which selected physical constants have been set to 1 through nondimensionalization of physical units.For example, the speed of light c may be set to 1, and it may then be omitted, equating mass and energy directly E = m rather than using c as a conversion factor in the typical mass–energy equivalence equation E = mc 2.
AOL Mail welcomes Verizon customers to our safe and delightful email experience!