Luminaire Data - Polar Curves & Valid Lamps

 

 

Polar-curve data may be measured using either the 'C-gamma' system or the 'Horizontal - Vertical' system (see CIBSE Technical Memorandum 14 for further information on these systems).

 

The C-gamma system allows both point and linear sources to be defined in the same manner.

 

A maximum of 12 'C' (or 'H') angles and 55 'gamma' (or 'V') angles can be defined when the data is entered interactively. For example, for a symmetrical luminaire this allows the C angles to be in steps of fifteen degrees from 0 to 180, and the gamma angles to be in 5-degree steps from 0 to 180. Such a large number of polar points will allow almost any type of polar curve to be defined, yet not all values need to be entered when specifying simple symmetrical polar curves. You can define the actual angles; in this way a large number of points can be specified where the curve is rapidly changing and fewer where the curve is changing little. The luminous intensities should all be expressed in terms of candelas per thousand lumens. Note that if the data are entered from a standard format file using the database facility, 72 C angles and 55 gamma angles can be defined.

 

Default:                        1

Warning Limits:           1 to 2

Error Limits:                 1 to 2

 

Intensity distributions from luminaires can be measured using two principal co-ordinate systems,'C-Gamma' or 'Horizontal-Vertical (H-V)'. Most interior luminaires are photometer

ed using the C-Gamma system whereas floodlights (due to their intensity distribution) usually are photometered in H-V. Enter the respective number of type of photometry:

 

·       1 = C-gamma notation (default)

·       2 = Horizontal-Vertical notation

 

Units:                           degrees

Default:                        0.0

Warning Limits:           0.0 to 10.0

Error Limits:                 0.0 to 30.0

 

The design attitude is the angle at which the luminaire is designed to operate. For normal indoor luminaires it is zero.

 

Units:                           degrees

Default:                        0

Warning Limits:           0 to 359

Error Limits:                 0 to 359

 

Up to twelve C Angles (or Horizontal angles) can be entered in ascending order, from 0 to 359 degrees. A blank line assumes a value of 0. The program will copy quadrants, so that if the last value entered was 90, the program will copy the other 3 quadrants, or if the last value was 180 then it will copy 2 quadrants. Otherwise you must complete the series, e.g. 0, 30, 60...330 or 0, 45...315.

 

Note that if data is read in from manufacturers' data, e.g. in CIBSE format, up to 72 C Angles can be read in.

 

Units:                           degrees

Warning Limits:           0 to 180

Error Limits:                 0 to 180

 

A maximum of 55 gamma (or V) angles can be entered , but only one per line. These can be in any order although no value should be repeated.

 

Units:                           cd/1000 lm

Warning Limits:           0 to 500

Error Limits:                 0 to 50000

 

Up to 12 luminous intensities can be entered on one line, for the same gamma (or V) angle, these apply to the various C (or H) angles entered above. The number of values to be entered depends on the choice of C (or H) angles.

 

 

 

Up to 20 valid lamps may be specified for each luminaire. For a linear fluorescent fitting for instance you may wish to define the various lengths, such as 1200, 1500 and 1800. Alternatively, a high-bay fitting may be capable of taking a SON lamp or a MBF lamp. For each valid lamp a number of other relevant pieces of data are required, such as the length and wattage, which will depend upon the lamp being used.

 

The valid-lamp reference, which may be up to 6 characters in length, is used as a key to pick up a lamp in the lamp database, so in order for you to use a particular lamp with your luminaire, the lamp must exist in the lamp database as well as being defined as a valid lamp for your luminaire. If you cannot remember the name of a valid lamp for a particular luminaire, the data can be reviewed by selecting the review database option.

 

Units:                           W

Warning Limits:           10 to 1000

Error Limits:                 0 to 10000

 

The luminaire wattage is the TOTAL power consumed by the lamps AND control gear and is used by the program to calculate the total wattage for a particular lighting scheme.

 

Units:                           VA

Warning Limits:           10 to 1000

Error Limits:                 0 to 10000

 

The luminaire voltamperes are the apparent power consumed by the luminaire. It is the product of the total current input to the luminaire and the supply voltage.

 

Units:                           m

Warning Limits:           0.0 to 2.4

Error Limits:                 0.0 to 5.0

 

The luminaire length measured in metres, is used to check whether the luminaire will fit in the room and also to calculate the glare-correction factor.

 

Default:                        m

Warning Limits:           0.9 to 1.1

Error Limits:                 0.5 to 2.0

 

The utilisation-factor correction factor is used to convert the UF data when the standard is not being used. It is also applied to the polar-curve data.

 

Units:                           1.0

Warning Limits:           0.8 to 1.2

Error Limits:                 0.5 to 1.5

 

The ballast-correction factor is the ratio of the light output of a reference lamp operated under reference conditions on a test ballast to the light output of the same lamp operated under the same conditions on a reference ballast.

 

One of the following glare-shape codes should be entered (as defined in the CIBSE Technical Memorandum Number 14 ):

 

 

Units:                           sq.m

Default:                        W x L

Warning Limits:           0.0 to 1.3

Error Limits:                 0.0 to 2.4

 

The luminous areas are used by the program when calculating glare indices from basic principles. The default value is calculated from the product of the luminaire width and length for this lamp.

 

Units:                           sq.m

Default:                        L x H

Warning Limits:           0.0 to 1.0

Error Limits:                 0.0 to 2.0

 

The luminous area is used by the program when calculating glare indices from basic principles. The side luminous area is similar to the base luminous area. The default is the product of the luminaire height and length of this lamp.

 

Units:                           sq.m

Default:                        W x H

Warning Limits:           0.0 to 1.0

Error Limits:                 0.0 to 2.0

 

The luminous area is used by the program when calculating glare indices from basic principles. The end luminous area is similar to the base luminous area. The default is the product of the luminaire width and height for this lamp.