都是磁场强度的单位.

1 特斯拉(TESLA)=10000高斯(GAUSS)=1韦伯/m² (Wb/m^2).

高斯比较好记,因为有高斯计.

我在过去设计扬声器单元时,总希望有8000高斯啊.

那不是说8就是"发"的年代,但是还是希望新单元的磁场测下来至少8000以上.

大的单元,1万也不过瘾.

记得去年有朋友问过上述单位的换算,我告诉他这些,

並说,先不要问什么,先死记,有时间再去加深理解.

贴些东西,大家参考.

SI UNITS

SI = System International Units

1. Quantity, Name, Symbol
2. SI Prefixes
3. SI Derived Units
4. cgs Units

QUANTITY, NAME, SYMBOL

length

metre (meter): m

(the correct English spelling of the unit is "metre", but the variant "meter" is frequently used in the United States)

mass

kilogram: kg

time

second: s

electric current

ampere: A

thermodynamic temperature

kelvin: K

amount of substance

mole: mol

luminous intensity

candela: cd

SI PREFIXES

exponent (base 10) of decimal numbers: E n = 10ⁿ

Factor           Prefix   Symbol

1024     E 24     yotta    Y
1021     E 21     zetta    Z
1018     E 18     exa      E
1015     E 15     peta     P
1012     E 12     tera     T
109      E  9     giga     G
106      E  6     mega     M
103      E  3     kilo     k
102      E  2     hecto    h
101      E  1     deca     da
10-1     E -1     deci     d
10-2     E -2     centi    c
10-3     E -3     milli    m
10-6     E -6     micro    µ
10-9     E -9     nano     n
10-12    E-12     pico     p
10-15    E-15     femto    f
10-18    E-18     atto     a
10-21    E-21     zepto    z
10-24    E-24     yocto    y

SI DERIVED UNITS

Frequency

hertz: Hz = 1/s

Force

newton: N = m kg/s²

Pressure, stress

pascal: Pa = N/m² = kg/m s²

Energy, work, quantity of heat

joule: J = N m = m² kg/s²

Power, radiant flux

watt: W = J/s = m² kg/s³

Quantity of electricity, electric charge

coulomb: C = s A

Electric potential

volt: V = W/A = m² kg/s³ A

Capacitance

farad: F = C/V = s⁴ A²/m² kg

Electric resistance

ohm: Omega = V/A = m² kg/s³ A²

Conductance

siemens: S = A/V = s³ A²/m² kg

Magnetic flux

weber: Wb = V s = m² kg/s² A

Magnetic flux density, magnetic induction

tesla: T = Wb/m² = kg/s² A

Inductance

henry: H = Wb/A = m² kg/s² A²

Luminous flux

lumen: lm = cd sr

Illuminance

lux: lx = lm/m² = cd sr/m²

Activity (ionizing radiations)

becquerel: Bq = 1/s

Absorbed dose

gray: Gy = J/kg = m²/s²

Dynamic viscosity

pascal second: Pa s = kg/m s

Moment of force

metre newton: N m = m² kg/s²

Surface tension

newton per metre: N/m = kg/s²

Heat flux density, irradiance

watt per square metre: W/m² = kg/s³

Heat capacity, entropy

joule per kelvin: J/K = m² kg/s² K

Specific heat capacity, specific entropy

joule per kilogram kelvin: J/kg K = m²/s² K

Specific energy

joule per kilogram: J/kg = m²/s²

Thermal conductivity

watt per metre kelvin: W/m K = m kg/s³ K

Energy density

joule per cubic metre: J/m³ = kg/m s²

Electric field strength

volt per metre: V/m = m kg/s³ A

Electric charge density

coulomb per cubic metre: C/m³ = s A/m³

Electric displacement, electric flux density

coulomb per square metre: C/m² = s A/m²

Permittivity

farad per metre: F/m = s⁴ A²/m³ kg

Permeability

henry per metre: H/m = m kg/s² A²

Molar energy

joule per mole: J/mol = m² kg/s² mol

Molar entropy, molar heat capacity

joule per mole kelvin: J/mol K = m² kg/s² K mol

Exposure (ionizing radiations)

coulomb per kilogram: C/kg = s A/kg

Absorbed dose rate

gray per second: Gy/s = m²/s³

CGS UNITS

erg

1 erg = 10^-7 J

dyne

1 dyn = 10^-5 N

poise

1 P = 1 dyn s/cm² = 0.1 Pa s

stokes

1 St = 1 cm²/s = 10^-4 m²/s

gauss

1 G = 10^-4 T

oersted

1 Oe = (1000/(4 pi)) A/m

maxwell

1 Mx = 10^-8 Wb

stilb

1 sb = 1 cd/cm² = 10⁴ cd/m²

phot

1 ph = 10⁴ lx

• Conversion of units
• Index General chemistry

• The NIST Reference on Constants, Units, and Uncertainty
  • International System of Units (SI): SI Units
  • SI Prefixes
• The International System of Units (SI) (BIPM)
• A Dictionary of Measures, Units and Conversions

好东西呀，谢谢扬老师~~~~~~~~~~

顶

顶

看不懂

多谢杨老师

不错！顶~

顶

多谢老兵!

请教：目前人工可以生产得到的喇叭单元用磁钢，设计优秀并实用的单元磁钢磁隙中，最高可以达到多少高斯？理论极限又是多少呢？这个问题与喇叭的性能息息相关的。

上面这个问题问得好.

求解途经似乎有三:

1.可请教磁学专家,比如姚云甫先生,可参看

http://www.bjx.com.cn/files//wx/cxcljqj/2001-2/11.htm

他与扬声器厂的联系不少.

2.用FINRMOTOR软件来模拟,也许磁体材料数据不够,但是我在几年前用过,在大多情况下是够了.

3.大家讨论.

杨老师,FINEMOTOR对于计算好象没有限制,只要你输入足够大和足够高性能的磁铁可以得到50,000Gs以上.新的版本不知道是否有导磁材料限制.

我实际测量到的最高值是1.8Tesla.

谢谢杨老师！谢谢随便说说兄弟！

1.8Tesla!很好了.专业档的音头吧?

的确，FM的磁路限制太少了，很多时候都怀疑它的真实性，这段时间都不怎么用来做前期分析了，一般都用来做同类结构的对比。

实测的三明治结构内磁的磁路，最高做过1.3T，再高估计要换玻莫合金了...

有道理.

对于FINEMOTOR得到的B值,一开始使用时,我们也不敢相信.用它是看一种可能的趋向.它的预计B值只能参考.最后的结果还是要实测B啊.

而且,B值的测量,平常是用基于霍尔效应的高斯计,但是真要准确的,我还是相信那种拉出音圈测电流的古典方法

用FINEMOTOR是有条件的.

1.3T也是不简单的了.

比起二十多年前的扬声器单元的开发,磁材料的进展带来了的好处可不是一两句话能讲完的.

姚先生很热情的,问他还是会有收获的.

老兵老师的题目很好啊，在学校的时候，经常被这两个单位制折腾得晕头转向！工作以后什么“达因”，什么“牛顿”不管了，就记住“T”和“G”的转换关系，一天光噻！

上去!

再顶上去让大家学习学习！！