18.6. Types of measurements
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## 18.6. Types of measurements

All supported measurement types are listed below, each with an example of the standard usage for such measurements.

Таблица 18.1. List of measurement types

Typ | Class | Standardunit | Description
--- | --- | --- | ---
Acceleration | Zend_Measure_Acceleration | Meter per square second | `m/s²` | `Zend_Measure_Acceleration` covers the physical factor of acceleration.
Angle | Zend_Measure_Angle | Radiant | `rad` | `Zend_Measure_Angle` covers angular dimensions.
Area | Zend_Measure_Area | Square meter | `m²` | `Zend_Measure_Area` covers square measures.
Binary | Zend_Measure_Binary | Byte | `b` | `Zend_Measure_Binary` covers binary convertions.
Capacitance | Zend_Measure_Capacitance | Farad | `F` | `Zend_Measure_Capacitance` covers physical factor of capacitance.
Cooking volumes | Zend_Measure_Cooking_Volume | Cubic meter | `m³` | `Zend_Measure_Cooking_Volume` covers volumes which are used for cooking or written in cookbooks.
Cooking weights | Zend_Measure_Cooking_Weight | Gram | `g` | `Zend_Measure_Cooking_Weight` covers the weights which are used for cooking or written in cookbooks.
Current | Zend_Measure_Current | Ampere | `A` | `Zend_Measure_Current` covers the physical factor of current.
Density | Zend_Measure_Density | Kilogram per cubic meter | `kg/m³` | `Zend_Measure_Density` covers the physical factor of density.
Energy | Zend_Measure_Energy | Joule | `J` | `Zend_Measure_Energy` covers the physical factor of energy.
Force | Zend_Measure_Force | Newton | `N` | `Zend_Measure_Force` covers the physical factor of force.
Flow (mass) | Zend_Measure_Flow_Mass | Kilogram per second | `kg/s` | `Zend_Measure_Flow_Mass` covers the physical factor of flow rate. The weight of the flowing mass is used as reference point within this class.
Flow (mole) | Zend_Measure_Flow_Mole | Mole per second | `mol/s` | `Zend_Measure_Flow_Mole` covers the physical factor of flow rate. The density of the flowing mass is used as reference point within this class.
Flow (volume) | Zend_Measure_Flow_Volume | Cubic meter per second | `m³/s` | `Zend_Measure_Flow_Volume` covers the physical factor of flow rate. The volume of the flowing mass is used as reference point within this class.
Frequency | Zend_Measure_Frequency | Hertz | `Hz` | `Zend_Measure_Frequency` covers the physical factor of frequency.
Illumination | Zend_Measure_Illumination | Lux | `lx` | `Zend_Measure_Illumination` covers the physical factor of light density.
Length | Zend_Measure_Length | Meter | `m` | `Zend_Measure_Length` covers the physical factor of length.
Lightness | Zend_Measure_Lightness | Candela per square meter | `cd/m²` | `Zend_Measure_Ligntness` covers the physical factor of light energy.
Number | Zend_Measure_Number | Decimal | `(10)` | `Zend_Measure_Number` converts between number formats.
Power | Zend_Measure_Power | Watt | `W` | `Zend_Measure_Power` covers the physical factor of power.
Pressure | Zend_Measure_Pressure | Newton per square meter | `N/m²` | `Zend_Measure_Pressure` covers the physical factor of pressure.
Speed | Zend_Measure_Speed | Meter per second | `m/s` | `Zend_Measure_Speed` covers the physical factor of speed.
Temperature | Zend_Measure_Temperature | Kelvin | `K` | `Zend_Measure_Temperature` covers the physical factor of temperature.
Torque | Zend_Measure_Torque | Newton meter | `Nm` | `Zend_Measure_Torque` covers the physical factor of torque.
Viscosity (dynamic) | Zend_Measure_Viscosity_Dynamic | Kilogram per meter second | `kg/ms` | `Zend_Measure_Viscosity_Dynamic` covers the physical factor of viscosity. The weight of the fluid is used as reference point within this class.
Viscosity (kinematic) | Zend_Measure_Viscosity_Kinematic | Square meter per second | `m²/s` | `Zend_Measure_Viscosity_Kinematic` covers the physical factor of viscosity. The distance of the flown fluid is used as reference point within this class.
Volume | Zend_Measure_Volume | Cubic meter | `m³` | `Zend_Measure_Volume` covers the physical factor of volume (content).
Weight | Zend_Measure_Weight | Kilogram | `kg` | `Zend_Measure_Weight` covers the physical factor of weight.

### 18.6.1. Hints for Zend_Measure_Binary

Some popular binary conventions, include terms like kilo-, mega-, giga, etc. in normal language use imply base 10, such as 1000 or 10³. However, in the binary format for computers these terms have to be seen for a convertion factor of 1024 instead of 1000. To preclude confusions a few years ago the notation BI was introduced. Instead of kilobyte, kibibyte for kilo-binary-byte should be used.

In the class BINARY both notations can be found, such as `KILOBYTE = 1024 - binary conputer conversion KIBIBYTE = 1024 - new notation KILO_BINARY_BYTE = 1024 - new`, or the notation, long format `KILOBYTE_SI = 1000 - SI notation for kilo (1000)`. DVDs for example are marked with the SI-notation, but almost all harddisks are marked in computer binary notation.

### 18.6.2. Hints for Zend_Measure_Number

The best known number format is the decimal system. Additionaly this class supports the octal system, the hexadecimal system, the binary system, the roman number system and some other less popular systems. Note that only the decimal part of numbers is handled. Any fractional part will be stripped.

### 18.6.3. Roman numbers

For the roman numbersystem digits greater 4000 are supported. In reality these digits are shown with a crossbeam on top of the digit. As the crossbeam can not be shown within the computer, an underline has to be used instead of it.

    <?php
    require_once 'Zend/Measure/Number.php';

    $great = '_X';
    $locale = new Zend_Locale('en');
    $unit = new Zend_Measure($great,Zend_Measure_Number::ROMAN, $locale);

    // convert to the decimal system
    echo $unit->convertTo(Zend_Measure_Number::DECIMAL);
    ?>

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