| Status: |
STD 2005/06/07 |
| Code: |
159 |
| Symbol: |
Np |
| EQ label: |
FIELD_OR_POWER_LEVEL_DIFF |
| |
| Quantities associated with this Unit |
|---|
|
| Quantity: |
level difference of two field quantities
|
| Concept definition: |
The difference between two levels of field quantities with the same reference F0. The level of a field quantity is LF = ln (F/F0), where F and F0 represent two field quantities of the same kind, F0 being a reference quantity.
1 Np is the level of a field quantity when ln (F/F0) = 1, i.e. F/F0 = e. |
| |
| Reference type: |
PR |
| Reference: |
[ISO 80000-3:2006, item 3-21.a] |
| Supplemental references: |
|
|
| Quantity: |
level difference of two power quantities
|
| Concept definition: |
The difference between two levels of power quantities with the same reference P0. The level of a power quantity is LP = (1/2) ln (P/P0), where P and P0 represent two power quantities of the same kind, P0 being a reference quantity. |
| |
| Reference type: |
PR |
| Reference: |
[ISO 80000-3:2006, item 3-22.a] |
| Supplemental references: |
|
|
| Quantity: |
logarithmic decrement
|
| Concept definition: |
δT, where δ is damping coefficient [ISO 80000-3:2006, item 3-23] and T is period [ISO 80000-3:2006, item 3-12]. |
| |
| Reference type: |
PR |
| Reference: |
[ISO 80000-3:2006, item 3-24.b] |
| Supplemental references: |
|
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