BRUEL & KJAER 1101 User manual

InstructionManual
Luminance Meter Type 1101
The Luminance Meter is light, portable and
battery powered. It is designed to measure
luminance simply and directly. Its two Mea-
surement-Field Angles, i.e.
1/3° and 1 o, give
it a measuring range that spans from
0,01 cd/m
2
to 2000 kcd/m
2• The measured
values are displayed numerically both in the
viewfinder and externally on the
top panel.
The readings are inherently stable due to an
internal automatic calibration of the zero
point. It is spectrally matched
to the CIE
standardized curve for human photopic vi-
sion. There are special averaging and peak
detecting circuits which allow it to be used
for flickering light sources such as fluores-
cent lighting, cinema screens, visual display
units etc. There is an output for tape and
level recorders.
+ Bri.iel &· Kjcer

LUMINANCE METER
TYPE
1101
From serial no. 1143107
October 1985

SAFETY CONSIDERATIONS
This apparatus has been designed and tested according to IEC Publication 348, Safety
Requirements
for Electronic Measuring Apparatus, and has been supplied in safe condi-
tion. The present Instruction Manual contains information and warnings which should be
followed by the user to ensure safe operation and to retain the apparatus in safe condi-
tion. Special note should be made of the following:
WARNINGS
Whenever it likely that the correct function or operating safety of the apparatus has
been impaired, the
apparatus must be made inoperative and be secured against unin-
tended operation.
When changing fuses
disconnect external power supply and/or remove at least one
internal cell
Any adjustment, maintenance and repair of the open apparatus under voltage must be
avoided as
far as possible and, if unavoidable, must be carried out only by trained
service personnel.

CONTENTS
1. INTRODUCTION AND SPECIFICATIONS {PRODUCT DATA) .............................................................................. 1
2. CONTROLS.................................................................................................................................................................. 5
2.1. FRONT PANEL........................................................................................................................5
2.2. REAR PANEL ..........................................................................................................................6
2.3. TOP AND SIDE PANELS .......................................................................................................9
3. OPERATION .. ............................................................................................................................................................. 11
3.1. PRELIMINARY ...................................................................................................................... 11
Environment and Handling.................................................................................................. 11
Internal Battery Supplies..................................................................................................... 11
External Power Supplies and Charging............................................................................12
Grounding Considerations..................................................................................................
13
Fuses .....................................................................................................................................14
3.2. SETTING
UP THE INSTRUMENT FOR MEASUREMENTS ............................................. 14
Power Check ........................................................................................................................14
Eyepiece Adjustment...........................................................................................................14
Objective Adjustment ..........................................................................................................15
Measurement-Field Angle ...................................................................................................
15
Entrance Pupil ...................................................................................................................... 17
Close-Up Lens...................................................................................................................... 17
3.3. MEASUREMENTS ................................................................................................................17
Auto-Range........................................................................................................................... 18
Range Setting (used with Average, Max. Aver. and Peak) ............................................
18
Average ................................................................................................................................. 19
Max. Aver.............................................................................................................................. 19
Peak....................................................................................................................................... 20
3.4. ADDITIONAL MEASUREMENTS ........................................................................................ 20
Illuminance ............................................................................................................................ 20
Luminous Intensity............................................................................................................... 21
Luminous Flux ...................................................................................................................... 22
4. USE WITH OTHER INSTRUMENTS....................................................................................................................... 23
4.1. GENERAL..............................................................................................................................
23
Use with the B & K Type 2317 Level Recorder................................................................ 23
5. SERVICE AND REPAIR............................................................................................................................................ 25

USES:
Typical examples
of luminance measurements:
• Workplace lighting
• Light sources and luminaires
• Reflecting surfaces
• Cinema and TV screens
• Visual display units
• Road and traffic lighting
• Signal lamps
•
Airport runway lighting
• Studio lighting
• Pulsating and rotating light sources
• Interior and exterior lighting environments
Furthermore
• Measurement of contributing illuminance from
source in the measurement field
The B &K Luminance Meter Type
1101 is designed for measuring lumi-
nance precisely, simply and directly.
Two Measurement-Field Angles, viz.
1 /3 ° and 1°, give the Type 1101 a mea-
suring range that spans from 0,01 cd/m
2
to 2000kcd/tn2•
The measured luminance values dis-
played in the viewfinder and externally
remove all guesswork from
the measure-
ments. The readings are inherently sta -
ble down to a resolution of 0,01 cd/m
2
due to the internal automatic calibr:a-
tion of the zero point. The Type 1101 is
spectrally matched to
the CIE stan-
dardized curve for human photopic vi-
sion.
Special averaging
and peak detecting
circuits allow
the Type 1101 to be used
for flickering light sources such as fluo-
rescent lighting, cinema screens, visual
display
units etc.
A signal
output is provided for con-
nection to tape and level recorders, os-
cilloscopes, and frequency analyzers.
The Type 1101 is battery powered
and is amply suitable for use
in the field
as well as in the laboratory.
BP0431-12
type 1101
Luminance Meter
FEATURES:
• Bright magnified view of measurement field
• Measurement-Field Angles
of 1f3° and 1o
• Matched to the relative spectral responsivity of
the human eye according to the CIE standardized
curve
for photopic vision
• Direct luminance measurements in cd/m
2
• Measuring range from 0,01 cd/m
2 to 2000
kcd/m
2
• Numerical readings visible in viewfinder as well as
on external liquid crystal display
• Automatic as well as user selectable range setting
• Simple-to-use split-image focusing
• Automatic zero point calibration
• Additionally max. average and peak readings
• Signal output
• Battery powered
• Externally powered

Introduction
The B & K Luminance Meter Type
1101 is simple to use. All that is re-
quired of the user is to aim the instru-
ment, via its viewfinder, at the light
source to be measured , adjust the fo-
cu s, and read off the numericall y dis-
played value of the luminance.
Two selectable measurement areas
are visible in the viewfinder, (Fig. 1).
These are circumscribed by two con-
centric circles in the centre of the field
of view and correspond with 1/ 3° and
1o Measurement-Field Angles. For
each Measurement-Field Angle there
are five sensitivity ranges which to-
gether span from 0,01 cd/m
2
to
2000kcd/m
2•
Also visible in the viewfinder are the
split - image focusing, an angular scale
from 1°
to 5° and a LED numerical
display. The split-image focusing is
similar to that found in many cam-
eras.
Fi g. 1 View through eyepiece s howin g 1°
and I /. 3° t ar get areas
Once the Type 1101 is set up and
focused on a particular object the lu -
minance will be given on the internal
display (visible in the viewfinder) as
well as on the external liquid crystal
display mounted on the top of the in-
strument .
Description
The 1101 has two optical systems,
i.e. measurement optics and viewfind-
er optics, both are illustrated in sim-
plified form in Fig. 2.
Measurement Optics
The objective lens A con s ists of
three single lenses which minimi se
chromatic and spherical aberration.
Light rays are focused at point C after
first passing through the glass disc B.
The disc B, which forms a fixed aper -
ture stop, ensures that the converging
2
Fi g. 2 O pti cal system of Type 1101
light subtends a constant solid angle
at C.
At C there is a two stop aperture
used for selecting the Measurement-
Field Angle via the appropriate knob
on the rear panel of the Type 1101
(Fig. 5).
Behind C lies the combined filter D
and light sensitive silicon detector E
which together match the Type 1101
to the V(.\) function for photopic vi-
sion. Fig. 4 shows a
typical response
function s*(.\)rel for the Type 1101 and
the absolute deviation from the V(.\)
function as they appear on the indi-
vidual calibration chart supplied with
each Type 1101.
Relative Spectral Responsivity
The response function given on each
calibration chart is the relative spec-
tral responsivity normalised in abso-
lute response against a standard A illu-
minant according to Ref. 2- 3 - 4. Since
the Type 1101 is in fact calibrated
against a standard A illuminant this
normalisation ensures that the instru-
ment's spectral measurement error can
be read directly from the deviation
curve. The match to the V(.\) function
is accordingly characterised through
the f{ error given as the integrated
numerical value of the deviation curve
divided by the integrated V(.\) func-
tion.
It is worth noting that a Japanese
standardised method (Ref. 5) of char-
acterising the error of the spectral
match exists which would specify the
Type 1101 to be within 1%.
Sensitivity to the Surrounding
Field
The measurement optics are de-
L
850181
signed to have very little sensitivity to
the field surrounding the measure -
ment-field. A numerical assessment of
this is the {2 error as proposed in Ref.
3-4 . The Type 1101 is individually
tested for this sensitivity on both
Measurement-Field Angles and the
maximum error found is quoted on
the calibration chart (Fig. 4).
Sensitivity to U V and I R Radia-
tion
Through careful design of the filter
D (Fig. 2) the Type 1101 is almost in-
sensitive
to U V and I R radiation. The
response limit is quoted in the specifi-
cations and is characterised according
to the CIE, see Ref . 3- 4.
Luminance M eter
TY J!e 1H>1
Fig. 3 Front pan el of Typ e 1101

Calibration Chart for
Luminance
Meter
Type 1101 • Seri
al no .: .....• .
.... 1 J.~~ . 1H ..............
Date : .. -- ·~-
.. ......... 2~ .•. 1:1 •. 1~~ ..
-aK,_ Signature: •
.•.... . .. JJ.S .
Normali:tedretaUve $pectt. altespon8Mty
Absotute <kWiatlon fi'On'l V (.\. ) Normalized relative
apeclral raaponsivlly
s'(l.~ . ~~t 25 'C
~'""'
s'( ~ ~-
~ /nm
s'( ~~.
380
0 . 0000
580
0.8667
390 590
0 .752 8
.00 Q.0014 600 0 .6256
410 0 . 0040
610
0. 4956
420 620
0.3730
430
0.0144 630 0.2649
-0.0220 600 0. 1778
450
0 . 0304
850 0. 11 41
-460
0.0478
660
0.0710
470
0.0838
670
0.0418
-460
0 . 1337
580 0. 0234
490
0.1888
890
0 .0124
500
0 . 3223 700 0,0065
510
0.5004
710 0. 0034
520
0.7001
720 0.
0018
530
0. 8689
730
0 .0 010
540 0. 9547 740 0
.0 006
550
0. 9859
750
0 .0 004
580
0.9829
760 •
0.0003
570 0 , 94'14 770 0.
0002
760
0.0003
L.__i......==. __ ___i ____ --~... ___ __::::~=o------lo , 1
Ref.,ences:
CIE P\lbliCallon No . 53, 1982
OtN 5032 (Oral!~ Part 6 and 7
700
Wavrt6ength.\
780nm
Match 10 V(A), f~: .. J.7.l .... ..... %
5ensl1tvtty to SIJffoundlng
,_, 1
2: . .
9. ,. ~JL .. .. •t.
850194
Fig. 4 Individual calibration chart as supplied with the Luminance Meter Type 1101
showing curves for the normalized relative spectral responsivity of the Luminance
Meter and the absolute deviation from the V(,.\)function. In this example the error in
match to the V(,.\)function, f/, is 1, 77 % and the sensitivity to the surrounding field,
f2, is 0,28 %. Note the five times enlarged scale for the deviation curve
Entrance Pupil
Various radii and locations of the
Entrance pupil are indicated on both
sides of the Type 1101. The Entrance
Pupil is the image of the aperture stop
B (Fig. 2). It is the apparent opening
of the measurement system as seen
from the object plane, and is used for
photometric calculations of illumi-
nance, luminous flux, and luminous
intensity.
Polarized Light
Since no mirrors are used in the
measurement optics of the instrument
the Type 1101 may be used for the
measurement of polarized light.
Close-Up Lens
With the supplied Close-Up Lens
SB 0015 fitted the measurement-dis-
tance from the front end of the Close-
Up Lens ranges from 0,25 m to 0,5 m.
Illuminance and Luminous In-
tensity Measurements
Although the Type 1101 is primarily
designed to measure luminance direct-
ly in cd/m
2,
it can also be used to
determine contributing illuminance
directly in lux and to calculate lumi-
nous intensity in candela from the
light source in the measurement field.
For these purposes the Aperture
Adaptor DB 2657 is supplied with the
Type 1101.
Viewfinder Optics
A totally reflecting mirror F (Fig. 2)
diverts about 6% of the incoming light
towards a double prism G. The light
emerges from the prisms and focusses
on a transparent disc H which bears
the split-image focusing system. The
disc His mounted flush up against the
field lens J which bears the reticle and
directs the light rays onto the ocular
lens K in the eyepiece, Fig. 1 shows
the reticle and the split image system
as seen through the eyepiece.
The ocular lens K can be adjusted
from +2 dioptre to - 3 dioptre to suit
the individual eye. The light emerges
from the eyepiece through a glass disc
L. The exit pupil lies 15mm past this
glass disc, thereby allowing the use of
spectacles. The exit pupil is 5 mm in
diameter and matches the average size
of the eye's pupil.
Signal Processing
The light sensitive silicon detector
E (Fig. 2) produces an electrical signal
which is proportional to the light
striking it. This signal is then passed
on to the electronics of the Type 1101
for processing according to user selec-
table requirements, see SELECTOR
switch in Fig. 5. There are four possi-
ble ways of processing the signal, these
are described below (see also specifica-
tions):
Auto Range
Rapid response average value dis-
play with automatic range changing
and automatic zero setting. The most
universal position when the Type 1101
is used hand held.
Average
Slow response average value display
with manual range changing. Auto-
matic zero setting when the "Reset"
button (Fig. 3) is held pressed in. Used
to advantage when measuring low fre-
quency modulated signals or signals
with high crest factors.
Max. Average
Maximum average value display
with manual range changing. When
the "Reset" button is press' ed the cur-
rent reading is erased, zero setting
takes place and a new reading is dis-
played. Used for measuring spatia l
maxima.
Peak
Peak value displayed with manual
range changing. When the "Reset"
button is pressed the current reading
is erased, zero setting takes place and
a new reading is displayed. Used for
measuring the peak levels from pul-
sating light sources.
Zero Setting
Zero setting, whether manually or
automatically initiated, takes place to
cancel any drift errors in the Type
1101. Zero setting occurs when the
output of the light sensitive silicon de-
tector E (Fig. 2) is short circuited
thereby giving a true zero input to the
electronics for calibration.
Range
There are five manually selectable
ranges (see specifications and Fig. 5)
which are used in connection with the
Off.
MaattlttDenmark
Fig. 5 Rear panel of Type 1101
3

"Average", "Max. Aver." and "Peak"
settings. Both displays use special
warning
markers for indicating over-
range (exceeding highest possible nu-
merical display) and overload (exceed-
ing input range of electronics).
Output
A BNC output socket is provided on
the front panel (Fig. 3) for connecting
the Type 1101 to a graphic level re-
LUMINANCE RANGES:
Measurement-Field Angle
1/3°
Autorange
0-200 cd/m
2
0-2 kcd/m
2
0-20 kcd/m
2
0-200 kcd/m
2
0-2000 kcd/m
2
Measurement-Field Angle 1o
Autorange
0-20 cd/m
2
0-200 cd/m
2
0-2 kcd/m
2
0-20 kcd/m
2
0-200 kcd/m
2
SPECTRAL SENSITIVITY:
Corrected for the eye's spectral sensitivity
for photopic vision in accordance with the
definitive values of V(A) adopted by the CIE in
1970 for an observance angle of 2° (Ref. 1)
Wavelength Interval: 380nm to 780 nm
Tolerance: f1' error as specified by CIE <3%
at
25°C (Ref. 2-3- 4) and according to a
Japanese
standard (Ref. 5) <1%
UV Response: u<0,2% (Ref. 3-4)
IR Response: r < 0,2% (Ref. 3-4)
ABSOLUTE ACCURACY:
± 3% ± 1 digit at 25°C measured on a stan-
dard illuminant A source. The instrument is
calibrated
without the Protection Glass
SB 0503 fitted
APERTURE ADAPTOR DB 2657:
Sensitivity Factor:
10 -3 lux/nit
(1 nit= 1 cd/m
2) with 1
o Measurement-Field
Angle and
object at oo
Accuracy: ± 3%
MEASUREMENT OPTICS:
Measurement-Field Angles: 1/3 ° and 1o
Focusing Range: 0,6m from entrance pupil
(or 0,5m from front end of objective lens) to
co. Wfth Close-Up' Lens SB 0015:. 0,25m to
0,5 m, both from front end of Close-Up Lens
f-number: 2,5
Focal Length: 100 mm
Sensitivity to surrounding field: f2 (u) < 1%
as
specified by Ref. 3- 4
VIEWFINDER OPTICS:
Field of View: 11 o
Focusing: Split Image Focusing
Measurement-Field: Markings for
1/3° and
10
Ocular Adjustment: +2 to -3 dioptre
Magnification: 1,5 ·
DISPLAY:
In Viewfinder: 3 112 digit LED
External: 3112 digit liquid crystal
corder, e.g. the B & K Level Recorder
Type 2317, to give a plot of how lumi-
nance varies with time. It is calibrated
so that an output of 2V DC corre-
sponds with a full scale average dis-
play.
Power Supplies
The Type 1101 can be powered in
several ways. The most common is by
8 1,5V alkaline cells IEC LR6
Specifications 11 01
Update: Both displays are updated every
400ms
Both displays register the measured lumi-
nance In cd/m
2 and
the battery voltage
ELECTRONIC SIGNAL PROCESSING:
Autorange: Linear averaging over 100 ms ev-
ery 400 ms. Automatic zero setting between
each avera(;Jing
Average: Exponential averaging with a time
constant of200ms followed by linear averag-
ing over 100 ms every 400ms. When the ''Re-
set" button is held pressed, zero setting takes
place between each linear averaging. Output
voltage is exponentially averaged with a time
constant ot 200ms, there"is a hold p. eriod of
30 ms when"zero setting takes place
Max. Average: Exponential averaging with a
time constant of 200 ms followed by peak de-
tection. Output voltage as tor "Average"
Peak: The peak value is detected with a rise
time determined by the input amplifier. Out-
put voltage follows the signal's instantaneous
value
with an upper frequency limit deter-
mined by the input amplifier, It floats for
30 ms when zero setting takes place
The table below gives typical rise time values
and upper 3dB frequency limits for the
"Peak" setting
Upper
Range
cd/m
2 Rise time 3 dB
10%-90%
frequency
p 1f30 limit
20
200 1,4ms
300Hz
200 2k 450
J.lS 850Hz
2k 20k
40 J.lS
10kHz
20k 200k
40 J.lS
10kHz
200k 2000k
40 J.lS
10kHz
Display Hold: When pressed one~ the current
reading is held
Reset: Releases Display Hqld, erases current
Max. Average and Peak reading and initiates
zero setting ' of the amplifier for 30ms
Overload Margin: 2,5 times the full scale val-
ue of the display
Linearity Error: ± 0,1% F.S. ± 1 digit
BNC OUTPUT SOCKET:
Linearity Range: 0
to + 5 .V DC
Level: + 2V DC corresponds with full scale
average value
of the display
Output Impedance: 60 0
(QB 0013) or 8 1,2V NiCd recharge-
able cells (QB 0032). The rechargeable
cells
may be charged by the .B & K AC
Mains Battery Charger ZG 0113 or the
B & K AC Mains Power Supply
ZG 0199 which will also simultaneous-
ly power the Type 1101. Alternatively
the Type 1101 may be powered from
an external source of 6 to 20 V DC via
the "Ext. Power Supply" socket on the
front panel.
POWER SUPPLIES:
Internal: 8
QB 0013 alkaline penlight cells
(IEC/LR6) giving approximately 8 hours of
continuous use or 8 QB 0032. NiCd recharge-
able cells (optional)
giving approximately 3112
hours of continuous use
AC Mains Battery Charger ZG 0113: Charg-
ing of NiCd cells via DIN socket on front panel
Mains Power Supply ZG 0199: Charging of
NiGd cells and powering the Type 1101 via
DIN socket on the front panel
External source: 6 to 20 V DC. 1,5W. Switch~
able galvanic separation between instrument ·
ground and external supply ground
E"'VIRONMENJ:; .. < ,,
Temperature interval: -10 °C to +55 °C
Humidity: 90% Relative at 30°0
Mechanical Shock: 75 g in any direction
DIMENSIONS AND WEIGHTS:
Ty~e 1101 with batteries onl.y
Length: 198 mrn (7,8 in)
Width: 83 mm (3,3 in)
Height: 133 mm (5,2 in)
Weight: 2,3 kg (5,1Ib)
Carrying Case with accessories (excluding
instrument an~ batteries)
Length:
340mm (13,4in)
Width: 135 mm (5,3 in)
Height: 240 mm (9,41n)
Weight: 2,7 kg (5,91b)
ACCESSORIES INCLUDED:
1 Close-Up Len$ 2 dioptre .. ................ SB 0015
1 Aperture Adaptor ....... .. . ...... ............... DB 2657
1 Lens Dust
Cover .................... .. .. ...... .. .DD 0356
1 Eyepiece Cover ............. .. .......... .. .. ..... DD 0348
1 Lens Brush .... ........... ... ....... ... .... .. ....... .. QA 0138
1 ~rotection Glass ... .. ............... ... .. ..... . .. SB OS03
8 Alkaline Cells .. . .. . ... ............ .... .• ... .........QB 0013
1
7-pin DIN Plug......... ... . .. . .. .. ................ ... JP 0703
1 Coaxial BNC Plug.............................. .. JP 0035
1
Screwdriver ................................... .. .... QA 0040
2 Extra Fuses .... ~ . .. ......................, ... ......... VF 0042
1 Pistol Grip .....:':·.................... ... :'.L ..... . .. .DH 04Ei1
1 Carrying Case....... .. .................... .. ...... KE 6252
ACCESSORIES AVAILABLE:
Mains Power Supply....... ... ........ .. .... ..... ZG 0199
C~ble (for use ~ith ZG 0199) 'j: ;,. .. ... ..... AQ 003q
Battery Charger ..... .. ...................:.......... ZG 0113
Tripod .............:......................................... UA 0587
NiCd cell
(8 required)........ .. ..................QB 0032
REFERENCES:
1 Publication C,IE No. 18.2 (TC-1.2) 1983
2
Publication CIE No. 53 (T0-2.2) 1982
3
Draft CIE Technical Report TC-2.2 (Detec-
tors) April 1984
4
Draft DIN 5032 parts 6 and 7
5 Japanese Standard JIS C 1609 1983

2. CONTROLS
2.1. FRONT PANEL
OBJECTIVE:
OUTPUT:
Objective ------+--
Output -------+-- ~
luminance Meter
Type 1101
BrUel & Kjaer
ExL Power Supply
Ext. Power Supply -- +-- ----l
1 ...: :--- +----- Display Hold
Reset
r - ~~-r- --+------ Reset
Fig. 2.1. Front panel of Type 1101
Used in conjunction with the eyepiece for a1mmg and focusing the
Luminance Meter on the target before taking a reading. It is rotatable
for focusing to the measurement-distance which is between the En-
trance Pupil (see below) and the object plane i.e. 0,6 m to infinity .
When
fitted with the Close-Up Lens SB 0015 the measurement-distance
from the front end of the Close-Up Lens ranges from 0,25m to 0,5 m.
Coaxial BNC analogue output for connecting the Type 1101 to a re-
corder, e.g. the B & K Level Recorder Type 2317 (see chapter 4). It is
calibrated so that _an output of 2V corresponds with a full scale aver-
age display, and an output of 5V corresponds with the start of the
overload range. When zero setting is terminated, the output voltage
follows the luminance signal with the frequency limits quoted in the
specifications i.e. slowly for positions "Average" and "Max. Aver." and
rapidly for position "Peak".
5

External
Supply
+ 6 to 20 V DC
Power Supply
Ground
Charge
+ 12 V, 0,14 A
850264
Fig. 2.2. EXT. POWER SUPPLY socket connections (external view)
EXT. POWER SUPPLY:
DISPLAY HOLD:
RESET:
2.2. REAR PANEL
SELECTOR:
6
Seven-pin DIN socket accepting plug JP 0703 for connecting the Type
11 01 to an external DC power supply of 6 to 20 V. It is also used for
recharging NiCd cells in situ using the B & K AC Mains Battery Charg-
er ZG 0013 or the B & K AC Mains Power Supply ZG 0199 which can
also simultaneously power the Type 1101. See Fig. 2.2 for pin designa-
tions.
Warning! Do not attempt to recharge alkaline or ordinary dry cells.
Only rechargeable cells should be charged.
Push-button. When pressed the current reading displayed internally
and externally is held.
Push-button. When pressed releases "Display Hold" sets peak value
measurement to zero and initiates zero setting of the measurement
amplifier.
Six position rotary switch with the following choice of functions (see
also specifications in chapter 1 ):
"Off" The instrument is switched off when internal batteries are used. If
the instrument is powered externally then it should be switched off at
the external supply .
"Batt." Battery condition displayed in volts on both internal LED and
the external LCD.
"Auto Range" Rapid averaged value of luminance displayed with auto-
matic range changing and automatic zero setting. The most universal
position when the Type 1101 is used as a hand-held instrument.
"Average" Slow averaged value of luminance displayed with manual
range changing. Automatic zero setting when "Reset" is pressed. Used
to advantage when measuring low frequency modulated signals or sig-
nals with high peak to average ratios.

MEASUREMENT-FIELD ANGLE:
EYEPIECE:
011
1---+--- Measurement-Field Angle
Measureme nt -Field Angle
Fig. 2.3. Rear panel of Type 1101
"Max. Aver." Maximum averaged value of luminance displayed with
manual range changing. By pressing "Reset" the reading is erased and
an
automatic zero setting followed by a new reading takes place. This
position can be used for measuring spatial maxima.
"Peak" Peak value of luminance displayed with manual range chang-
ing. When the "Reset" button is pressed the current reading is erased,
zero setting takes place and a
new reading is displayed. Used in con-
junction with the ·"Average" setting to determine the peak: average ra-
tio for flickering light sources e.g. fluorescent lamps.
For any shift in setting between "Average", "Max. Aver.", and "Peak"
automatic zero setting takes place.
Five position rotary switch for selecting the upper limit of the measur-
ing range. There are five
positions for each Measurement-Field Angle.
Two position switch for selecting the Measurement-Field Angle i.e. 1o
or 1f3°. The Measurement-Field Angle varies slightly with the position
of the Entrance Pupil (Fig. 3.5). The ones quoted on the rear panel are
nominal values for a measurement-distance of infinity.
Used
for viewing, and aiming the instrument at, the target. It is adjust-
able to accommodate for the individual relaxed eye from +2 dioptre
(screwed fully out) to -3 dioptre (screwed fully in). There are white
bands
spaced out in dioptre around its barrel which signify the amount
of adjustment relative to a normal eye (0 dioptre, red band). Since the
exit pupil lies 15 mm past the ocular ring the user may wear glasses
and fold
back the rubber hood when looking into the eyepiece.
7

INTERNAL DISPLAY AND RETI-
CLE seen in eyepiece
3112 digit LED display of luminance reading in cd/m
2,
kcd/m
2 (qualified
by the appearence of
3 which means
multiply reading by 103 ), battery
condition in volts, over-range and overload. If an over-range (exceed-
ing highest possible numerical display) occurs then only the most sig-
nificant digit, i.e. 1, will appear flashing. If an overload (exceeding in-
put range of electronics) occurs then a vertical stroke will also appear
flashing to the left of the display.
(see Fig. 2.4):
The overload marker is displayed when the peak luminance exceeds
2,5 times the full scale averaged value. The marker disappears when
the
overload condition ceases.
When an
over-range condition ceases with the instrument set to
"Peak" or "Max. Aver." the reset button should be pressed to cancel
and update the display.
SPLIT-IMAGE FOCUSING
(see Fig. 2.4): Used
for focusing the instrument on the target by rotating the objec-
tive until the two halves of the image (target) line up with each other.
TARGET AREAS
(see Fig. 2.4): Two
concentric circles corresponding with Measurement-Field Angles
of 1/3° and 1o for circumscribing the image of a light source (target)
when
aiming the instrument.
ANGULAR SCALE 1
o to 5o
(see Fig. 2.4): Used
for measuring the angular distance between the target and adja-
cent light sources.
8
Target Areas for
Measurement
Field Angles of
1/3 ° and 1o
Flashes when Overloaded
Split - Image
Focusing
Flashes when in Over-range
Angular Scale
1o to 5°
851486
Fig. 2.4. View through eyepiece showing reticle, 1!3° and 1o target ar-
eas, split-image focusing and 1o to 5° angular scale .

2.3. TOP AND SIDE PANELS
EXTERNAL DISPLAY
(see Fig. 2.6):
Liquid Crystal Display
Fig. 2.5. Top and side panels of Type 1101
External 3112 digit LCD display of luminance in kcd/m
2 and
cd/m
2,
battery condition in volts, display hold, over-range and overload. If the
battery voltage falls below 7,2 V the word "bat" is displayed in the
bottom left hand corner. If an over-range (exceeding highest possible
numerical display)
occurs then only the most significant digit, i.e. 1,
will appear. If an overload (exceeding input range of electronics) oc-
curs then an arrow will also appear in the top left hand corner.
The overload
marker is displayed when the peak luminance exceeds
2,5
times the full scale averaged value. The marker disappears when
the overload
condition ceases.
The RESET
button should be pressed when an over-range condition
ceases with the instrument set to "Peak" or "Max. Aver."
Fig. 2.6. External LCD display showing all possible characters
9

ENTRANCE PUPIL
(see Fig. 2.5):
10
The horizontal line represents the axis of the measurement optics.
Each
vertical line represents the radius of the Entrance Pupil and its
position on the axis. A figure appears with each vertical line signifying
the distance between it and the object plane, these same figures are
repeated around the barrel
of the objective. The Entrance Pupil and its
use is
described in section 3.2.5.

3. OPERATION
3.1. PRELIMINARY
3.1.1. Environment and Handling
Temperature and Humidity
The
Luminance Meter Type 1101 can be operated in temperatures ranging from -10 to
+55°C (50 to 131 °F). The instrument may be operated in conditions of up to 90% rela-
tive humidity at 30°C (86° F). Avoid sudden changes of temperature since this may cause
condensation on the lenses of the measurement and the viewfinder optics thereby giving
rise to fogging. If condensation does occur, wait for a short period of time to allow it to
clear up before making any measurements.
Protection Glass SB 0503
When using the Type 1101 out of doors, use the Protection Glass SB 0503 to protect the
objective lens against rain and other extraneous matter. The Protection Glass is deliv-
ered screwed onto the barrel of the objective. Light loss through the Protection Glass
can be compensated for by multiplying the measurement result by a factor of 1,04.
Factory calibration of the Type 1101 is without the Protection Glass fitted.
Cleaning the Objective Lens
If the surface of the objective lens gets dusty or greasy the sensitivity to stray light is
considerably increased. The lens surface may be cleaned as follows: first gently remove
the
surface dust using the Lens Brush QU 0138, next take a soft tissue and moisten part
of it with a weak solution of detergent in water and gently rub the lens surface with it,
and finally,
wipe the lens with the dry part of the tissue taking care not to use excessive
pressure. Cleaning the
objective lens should be carried out only when necessary and as
seldom as possible.
Storage and Transport
When the
instrument is not in use place the Lens Dust Cover DO 0356 and the Eyepiece
Cover DO 0348 in position.
The instrument and its accessories are delivered in a protective carrying case KE 0252
which should always be used for storing the instrument when not in use.
3.1.2. Internal Battery Supplies
The
Instrument is delivered with 8 QB 0013 alkaline penlight cells (IEC/LR6} which will
give approximately 8 hours of continuous use. The cells are delivered stored under the
flap in the bottom of the carrying case. Alternatively 8 rechargeable NiCd cells (QB 0032)
giving approximately 3112 hours of continuous use may be used. The cells should be
placed in the base of the instrument which is accessible after unscrewing four retaining
11

screws and removing the base plate (Fig. 3.1 ). When installing the cells observe the
correct polarity which is indicated for each cell.
Once the cells have been installed they can be checked by setting the SELECTOR
switch
to "Batt." and observing the voltage reading on either the internal or external display.
For fresh alkaline cells the reading should be about 12 V, for fully charged NiCd cells the
reading should be
about 9,6 V. Once the battery voltage falls below 7,2 V the word "bat"
is displayed in the bottom left hand corner of the external LCD, this means that the cells
should be replaced
or recharged as necessary. Label the instrument to indicate which
type of cells (alkaline or rechargeable) are in use.
Fuse V 1
Ground
Switch
Fuse V2
Fig. 3. 1. Battery compartment in base of instrument showing ground-
ing switch and fuses
3.1.3. External Power Supplies and Charging
12
There are two ways of externally powering the Type 1101. Both make use of the EXT.
POWER SUPPLY socket on the front panel.
External 6 to 20 V DC
The
first of these is from an external DC supply of 6 to 20 V which should be applied
across pins 1 (positive) and 2 (negative-primary ground) of the EXT. POWER SUPPLY
socket using the DIN plug JP 0703 supplied, see Fig. 2.2. Insertion of the DIN plug will
isolate the internal cells.
Warning! Where a car battery is used and the positive terminal of the battery is connect-
ed to the body of the car, make certain that "Separate Ground" is selected via the
GROUND SWITCH shown in Fig. 3.1. This avoids the danger of short circuiting the bat-
tery, and possibly damaging the instrument, should the instrument case come into con-
tact with the car body.

B & K Power Supply (and Battery Charger) ZG .0199
The second makes use of the B& K Mains Power Supply ZG 0199 (Fig. 3.2.). It may be
powered from 50 to 400Hz AC mains at 100, 115, 127, 220 or 240 V single phase. It is
connected to the EXT. POWER SUPPLY socket of the Type 1101 by the control cable
AQ 0035 (apart from the charging circuit this will isolate the internal cells). When used,
the ZG 0199 will
power the Type 1101 as well as charge its internal NiCd cells. If non-
rechargeable cells are fitted in the Type 1101 the OUTPUT SELECTOR on the ZG 0199
must be switched to Drive Voltage "On" -Charge "Off". If, and only if, rechargeable
NiCd cells are
fitted in the Type 1101 set the CHARGE switch on the ZG 0199 to "On".
Fully discharged NiCd cells will take about 61 /2 hours to reach a fully charged condition.
Fig. 3.2. B & K Mains Power Supply ZG 0199
B &K Battery Charger ZG 0113
For charging internal NiCd cells the 8 & K Battery Charger ZG 0113 (Fig. 3.3) may be
used. It
may be powered from 50 to 400Hz AC mains from 100 to 130V AC and from
200 to 240 V AC single phase. It has an integral output cable with a 7 -pin DIN plug which
plugs into the EXT. POWER SUPPLY socket of the Type 1101 (apart from the charging
circuit this will isolate the internal cells). Fully discharged NiCd cells will take about 4112
hours to reach a fully charged condition. Only rechargeable NiCd cells may be charged.
Fig. 3.3. B & K
Battery Charger ZG 0113
3.1.4. Grounding Considerations
Indiscriminate grounding of equipment can result in ground loop interference. To prevent
this it is necessary to ensure that the signal, chassis and power ground lines of the Type
1101 and of other equipment with which it is used, are either isolated from ground or
grounded at only one point in the system.
13

3.1.5. Fuses
To facilitate grounding in accordance with the above, the Type 1101 is equipped with a
GROUND SWITCH which is
located under the baseplate shown in Fig. 3.1. Selection of
"Separate Ground" isolates the signal/chassis ground from the external ground of the
instrument, while "Common Ground" interconnects them. Normally the switch should be
kept set to "Common Ground", however, where the signal chassis/ground and the exter-
nal power ground of the Type 1101 are connected via external equipment "Separate
Ground" should be selected to prevent ground loops.
Two VF 0042 fuses, V1 and V 2, are located under the baseplate shown in Fig. 3.1. They
are
both rated at 315 rnA, V1 protects the instrument against excessive current coming
from an external power supply and V 2 protects the internal NiCd cells from excessive
charging current. Two spare fuses are supplied.
Warning: switch the instrument off and disconnect the Ext. Power Supply before chang-
ing the fuses.
Make sure that only fuses with the required rated current and of the specified type are
used
for replacement. The use of mended fuses and short-circuiting of fuse holders
should be avoided.
3.2. SETTING UP THE INSTRUMENT FOR MEASUREMENTS
The instrument may be operated hand-held using the pistol grip DH 0491 provided which
screws into the base or mounted on a tripod UA 0587. For survey measurements using
the 1o Measurement-Field Angle, hand-held operation will suffice. For measuring a maxi-
mum luminance use the "Max. Aver." setting of the SELECTOR switch, this will ensure
an
accurate reading even for an unsteady hand. For precision measurements, especially
when using the 1f3° Measurenalent-Field Angle, the instrument should be mounted on a
tripod. Furthermore, a panning head (available from most photographic suppliers) should
be mounted between the tripod and the instrument. Before commencing with any mea-
surements the instrument has to be set up according to the instructions and allied infor-
mation given below.
3.2.1. Power Check
Select "Batt." on the SELECTOR switch and observe the battery voltage on either dis-
play. The battery voltage should be greater than 7,2 V, if it falls close to 7,2 V then there
will be a very limited time before the the battery cells need replacing or recharging.
Once the battery voltage falls below 7,2 V the word "bat" will appear on the external
LCD, this means that the cells should be replaced or recharged as necessary, see sec-
tion 3.1.2.
3.2.2. Eyepiece Adjustment
14
The eyepiece can be adjusted to accommodate for the individual eye as follows. Look
through the eyepiece while rotating it until a the reticle (Fig. 2.4 chapter 2) comes into
focus: now turn the eyepiece clockwise by 112 dioptre, this last adjustment will ensure an
easier positioning of the objective when using the split image focusing. If spectacles are
worn, fold back the rubber hood on the eyepiece to give a more comfortable position of
the eye in relation to the eyepiece.