Brüel & Kjær 2305 Operating instructions

BRUEL & KJA:R
Nc:erUlj'l -Denmark Service Instructions
2305
High Speed Level Recorder
Consisting of:
E lectronic Section
Mechanica l Sect ion
Position
of Components
Parts list
Circuit Diagram
Removal of the Metal Case
2305.1
2305.2
2305.3
2305.4
2305.5
Pl ace the instrument foce downwards on a piece of 50ft material. Then remove bottom plate and back plate
remove the MO screws A and the cover
Trouble Shooting
remove
the four screws C and the two metal plates B
remove the fi ve screws D
remove 1:10 geor lever E
The meta l case con now be removed.
o
If the reason for a fault is not on obvious one such as 0 dead tube, broken down resistorI blown or disconnected fuse etc., then first
test the voltages of all the tubes and compare them with the volt ages shown in the circuit diagram in order to loca li ze the defec t.
Should this method of finding the fau lt prove unsuccessful t then check the i nstrument by adopting the method described in the ad just-
ment procedure. When the trouble has been found and remedied, thevoltagesand adjustments whi ch are influenced by the remedy mus t
be rechecked. •
The tolerances stated in the instructions can only be used as a guide for adjustment and control, but any deviations must not be corrected
wi thout being sure that the to lerance s of the instruments used for making the adjustment ore sa small as to ha ve no influence on t he
measurements.
T he inst ructions in this Manual are given purely as a guide tothe service of equipment. Some faults, as f. i nst., small deviations in
tolerances require for their correct ion special control equipment and extensive experience, and in these cases it is necessary to send
the instrument to the factory. '
Spare Ports
Pl ease state type and serial number of apparatus, when spare parts are ordered.
Instruments and accessories necessary for service and repair:
Mu lt imeter (50 I-IA)
Beat F requency Oscil l ator type 1 022
(Beat F requency Oscillator type 1 013)
(Beat F requency Osc i Ilator type 1 017)
Pressure Gage (15-1 50 gr)
El ectron ic Voltmeter type 2409
2305 -1 .65

BROEL & KJ.ER
NCBrum -Denmark
Electronic Section
2305.1
valid from seriaillo. 11 6350
sheet 1 .
~ l :;
;~~
;. e! .•! .!_
le22
1.1. Balance of the Output Amp lifier
POTENTIOMETER RANGE,"S'and by"
WR ITING SPEED:ulooo mm/s"
1 .2. Balance of the Input Ampl i fier
1 .3. Mechanical Friction and Max.Driving Power.
I NPUT ATTENUATOR,"O dB"
I NPU T POTENTIOMETER,"10"
WRITING
SPEED,"2 mm/s" (large !;gure)
LO W ER Ll M.FREQ.,"200 Hz"
REC TIFI ER RESPONSE,"RMS"
P
OT ENTI OMETER RANGE,"50 dB"
MOTOR,"On"
PAPER DRIVE:"Start-Forward"
PAPER SPEED,"l mm/s" (large !;gure)
l:l Ogearlever pushed i n.
P APER, QP 0402 (QP 0423)
305.1 - 1.65
[9
:.•. :: .. ..
Measure the d.c.voltage across Rl , measuring point B + B -: approx .5 V.
Then mea~re the d.c. voltage across the drive coil, measuring point B- and
ground: 0 - 10 V.
If unbalanced, connect 91 of tube V6 to ground, measuring point H.
Measure
the 5 kHz voltoge across the primary of transformer T3 by means of
type 2409 and ad ju st P13 115 kc/s campll to min. vol tage.
Then adjust:
P4 for apprax. 5 V across B+ and B-
PS for approx. 0 V across B- and ground
Remove ground
connection from measuring poi nt Hand adiust P7 "Chopper ba-
lance" to 0-6 V across the drive coil, measuring point B - and ground.
Possible reasons for zero drift: defective tubes V 1,6,7,8
derective diodes 0 1 4-17
Measure the voltage across the anodes of V9 and V l0 , measuring point C -D:
max. 10 V.
If necessary adjust PI "D. C .ba l ance".
Possible reason for unbalance: defective tubes V2 - 5,9, 10
Whenever V2 and V3 are changed only use selected l ow microphonic tubes.
Input signa l: 10 V 1 000 Hz.
Measure the d.c. voltage across the dr ive co il , measuring point B- and ground.
When the input signa l is disconnected the voltage should be below 20 V during
movement to 0 dB li ne. If the voltage is higher remo ve the driving arm from
the boogie and repeat the measurement.
If the voltage is: below 10 V check wri ting system item 2. 1.
above 10 V check magnet system item 2.2 .
When
the sapphire ~tops at the 0 dB I ine the voltage sh ould incr ease to opprox.
150 V.
Connect again the input signal. As long as the sapphire is moving the vol tage
should be approx. -20 Vand increas e to approx. -150 V when the system is
stopped.
Po ssible reaso ns for fault: defective tubes V1 ,6,7,8.

, 00 P,O 0 CJsB E,gm~ 0 00 O. 0 0i~ 0 0 'SO ..75mm 0 o . ~ 0 0 0 4jri;m 0 ~omrri' 0
"'"
/ , ,
, ,
/ , ,
, ,
, ,
I ,
, I
/ I ,
,
,
--_. -- -.- ---- -+----4--- - 1
1
Writing Speed: Smm/S 1000mmls
1.4. Writing Speed.
INPUT ATTENUATOR:"O dB"
INPUT POTENTIOMETER:"IO"
WRITING SPEED:"S mm/s (large flgure)
LOWER UM . FREQ .:"200 Hz"
RECTIFIER RESPONSE:"RMS"
POTENTIOMETER RANGE:"5O dB"
WRITING WIDTH:"50 mm"
MOTOR:"On"
PAPER DRIVE:"Stap-Forword"
PAPER SPEED: " IO mm / s (large figure)
I :10 gea r lever pushed in
PAPER: QP 0102 (QP 0123)
Input signal: 4 V 1000Hz.
Depress OSCILLATOR STOP on type 1022 wh;te the poper is running ( PAPER
DRIVE to "Startll}ond release it again when the s apphi re hos r eached the 0 -
dB line .
The paper length for a movement of the sapphire from 50 dB to 0 dB and back
ogain should be equal (62 mm) .
Tolerance: !
20% f.Aeosured on the peper: 50 -75 mm.
If necessary adjust P3 "V el.odj. U{anticlockwise for increased spe ed)
Possible reasons for faults : defective feed4:>qck coil
defective diodes Q 12, 13
unbalanced amplifier check item 1 .1 and 1.2.
b. WRITING SPEED to 1000 mm /s (large flgure) Check os under a
PAPER SPEED:"IOO mm /s" (large figure) Tolerance: :: 20 %
1:10 gear lever pushed in llE:asured on the paper: 4 - 6 mm.
If necessar y adjust P12 "M.ox . vel.odj." (clockwise for increased speed)
o 0 0 000000000
000000000000 0 0
&. , .... 6. .. ,_
Lower Lim Fteq.
200 50
2p
1p
2
Hz
I I I
-
..--
-
r--"1
,---,
r---
_.
') .. ~.~ ,
1.5. Overshoot
b.
INPUT AHENUATOR:"OdB"
INPU T POTENTIOMETER:"IO '
WRmNG SPEED :"800 "",,/." (10<90 r;gure)
LOWER LIM .FREQ.:"200 Hz "
RECTIF IER RE5PONSE:"RMS"
POTENTIOMETER iANGE:"50 dB "
MOTOR:"On"
PAPER DRIVE:"Stop-Forw",d"
PAPER SPEED:" 1; mm/s (1",11" ligo<e)
1:l 0 gear: rever pushed in
WRmN'G WIDTH:"5O mm "
PAPER: QP Ot02 (QP 0123)
WRITING SPEED
own/s
500
250
100
25
23115 .1 - I .65
Input signal: 400 mV 1000 Hz .
Dope ... and reloose OSCILLATOR STOP on type 1022 while the poper is run-
ni!)g_ PAPER DtlIVE to "Srort" .
Ovenhoot: """'. I mm.
If necessary odiust Pl0 -Resolution': Whenever P 10;s odiusted check item.t.6
Possible reason for faults: unbalanced amplifier check item 1.1and 1 .2 .
defective diodes Ql - 4
LOWER lIM. FREQ.
Hz
50
20
10
2
faulty contact in mcJ9let system check item 2 .2
writing speed too high check item 1.4
OVERSHOOT
I
1.5
I
1.5

BROEL & KJA:R
NCBrum - Denmark
Electronic Section
valid from set"iol no. 116350
2305.1
sheet 2.
OO ~frfr~OfrOOOODODDOO 00 0 0
-
-
--
- -
~ .
1.6. Resolving Power
a . INPUT ATTENUATOR:"10 dB"
INPUT POTENTIOMETER:"IO"
Br(.jel6.K,~
WR ITING SPEED:"16 mm/s" (la'ge figu,e)
LOWER LIM.FREQ .: "2oo Hz"
RECT IF IER RESPONSE:"RMS"
POTENTIOMETER RANGE:"50 dB"
MOTOR:"On"
PAPER DRIVE;IIStart-Forward"
PAPER SPEED:"1 mm/s (Ia'ge figu,e)
1 :10 gear lever pushed in
WR ITING WIDTH:"50 mm"
PAPER: QP 0102 (QP 0123)
1.7.Frequenc y Response 2-1000 Hz
a.INPUT ATTENUATOR:"O dB"
INPUT POTENTIOMETER:"10"
WRITING SPEED:"8 mm /s" (large figu,e)
LO WER LIM.FREQ."200 Hz"
RECTIFIER RESPONSE:"RMS"
POTENTIOMETER RANGE:;'50 dB"
b.Check all positions of
LOWER LIM.FREQ .
1 .8. Frequency Response 1 - 200 kHz
a.INPUT ATTENUATOR :' ''O dB"
INPUT POTENTIOMETER:"10"
WRITING SPEED:"5oo mm/s (Ia'ge figu,e)
LOWER LIM. FREQ. "200 Hz"
RECTIFIER RESPONSE:"RMS"
POTENTIOMETER RANGE:"50 dB"
b.Check all pooitions of
INPUT ATTENUATOR
305.1 - 1.65
I l l 1
I f 1
Frequency: 1000Hz.
Adjust the input voltage until the sapphire is on the 20 dB line.
Change INPUT ATTENUATOR to "0 dB
II
and back again - to 1110 dB" .
Thereafter to 1120 dB" and back ogcin to "lO dB".
Check that the sapphire comes back again to the 20 dB line .
Tolerance: ~ 0,5 mm
Possible reason for faulk: faulty adjusted Pl0 check item 1 .5
unbalanced amplifier check item 1.1 cnd 1.2
mechanical friction check item 1 .3
The tower limit can only be checked by means of a law frequency oscillator
f.inst. type 1017.
Frequency:1000 H z. Adjustthe input voltage until the sapphire is on the 4Od8
line .
Change frequency
from the O$cillotor according to position LOWER lIM.FRE Q.
Deflection of the sapphire: 40 dB .
Tolerance:
0.3 dB (+ to lerance of type 1017: 0.5 dB)
The upper limit can only be checked by means of a high frequency oscillator
f.inst. type 1013.
Frequency:looo Hz. Acqust the input voltage until the sapphire is on the 40dB
line.
Change frequency to 200 kHz.
Deflection of the sapphire: 40 dB
Tolerance: -0,2 - 0,5 dB (+ tolerance of type 1013: 0,5 dB)
Attenuator ,vep: 10 dB
Tolerance: - 0.2 dB

1 .9. Rectifier Response
INPUT ATTENUATOR,"O dB"
WRITING SPEED,"IOOmm/s"(la'ge I;gu,e)
LOWER LlM.FREQ.,"20 Hz"
RECTIFIER RESPONSE,"RMS"
POTENTIOMETER RANGE,"50 dB"
PAPER,QP 0102 (QP 0123)
h. RECTIFIER RESPONSE to "Averoge"
RECTIFIER RESPONSE to "Peak"
d. RECT IFIE R RESPONSE to "DC"
1. 1O.Mains Freq uency - 5 kHz Chopper Beat
a.INPUT ATTENUATOR:"O dB"
INPUT POTENTIOMETER:"10"
WRITING S
PEED: " I00 mm/s (la'ge flgu,e)
LOWER LlM.FREQ.:"10 Hz "
RECTIFIER RES PONSE," Peak"
POTENTIOMETER RANGE,"10 dB"
PAPER: QP 01 02 (QP 0123)
b.WRITING S PEED to "500 mm/s"(la'ge I;gu,e)
L
OW ER LlM . FREQ. to "200 Hz"
1.11 . Sen sitiv ity -Reference
a. INPUT ATTENUATOR :"O dB"
INPUT POTENTIOMETE R:"10"
b.
WRITING S PEED :"I00 mm / s" (la'ge (;9u,e)
LOWER LlM.FR EQ .:"20 Hz"
RECTIFIER RESPONSE : "RMS"
POTENTIOMETE R RANGE :"50 dB"
2305.1 - 1.65
Depress the "100 mV /Ref." button and adjust INPUT POTENTIOMETER until
,the sapphire is on the 20 dB line.
Releo5e the push-button and adjust the input voltage (frequency: 1000 Hz )
unt il the sapphire is on the 20 dB line .
Sa pph ire deflection: 19.1 dB
Sapphire deflection: 23 dB
Disconnect the oscillafor and co nn ec t a d .c. vo ltage 1. 5 V to INPUT socket
Sapphire
deflection: 37.5 dB
Inpu t signal : 15 mV 1 000 Hz .
Change the frequency slowly
from 1 kHz to mains frequency' and check th e
$Cpphire movement. At approx .2 Hz from mains frequency:. ma x. 0,5 mm beat
If necessary adjust P9 and P14 '"hum"
Change frequency to around 5 kH z: max.o .S rrm beat.
If necessary adjust P8 "5 kHz beat!!
Frequency:l
000 Hz . Adjust the input voltage until the sapphire is on the 0 dB
line .
Input voltag e: 5 - 6 mV
Adjustthe ;nput v oltageto exactly l00mVand adjust INPUT POTENTIOMETER
un til th e sapphire is on the 20 dB line.
Depress "100 mV Re f. II button and check the deviation: max. o . l dB.
If necessary ad just P2
u
l00 mV Ref. II

BROEL & KJJER
Ncsrum - Denmarlc
g.t.Writing System
a . Clean ing
b. Mechanical Friction
c. Paper guide clip .
POWER:"On
Il
MOTOR : "On"
MOTOR DRIVE :" Start -Forward"
PAPER SPEED :" 30 mm/s" (large figure)
t :10 gear lever pushed in
d .Stylus pressure
e.Adjustment
of dB scale
Mechanical Section
2305.2
valid from serial no. 199554 sheet 1.
Removewriting arm unitcoverby pulling cover to the right. lift stylus mechani-
cally by moving grooved finger cam A clockwise. Remove the driving arm from
the lug B. Unscrew the retaining screws C and carbfullylift the complete unit
off.
With a soft cloth and triclorethylene remove any wax or waste matter from writ-
te.g plate 0 and bottom plate E. Alsoclean the guide barsF and the guides G.
After cleaning pullout pin H and place it in the hole 1. Replace writing arm
unit and set it so that the distance to pin H is 0.5 rrvn, thus ensuring that unit
is accurately and squarely situated.
tv\easure the force necessary to move the writing system only. (Removethedriv-
ing arm from the lug 8) max.: 40 g.
The sapphire should rest on the paperI if the sapphire is lifted mechanically by
the finger cam
A, the force will be higher.
lift stylus mechanically by moving grooved finger cam A clockwise.
Adiust the paper guide
clip K by turning screw L to a position where the tension
is suitable for a smooth pull-off of paper from roll.
Check that the paper can run at least 30cm forward and backward several times
without
the paper tending to catch and thus tear at the perforations.
The screwdriver must be removed for each trial to avoid excess pressure on the
clip.
Check that the pressure is 18 - 21 g. If necessary adjust screw M
Set stylus to the position OdS on the paper and adjust the screw N for a corre-
sponding reading on the metallic scale.
ATTENTION. Under no circumstances should oil be applied to the writing system.
2305.2 - 1.67

A[l!JA
F G c B
----~~, I o
__ ___ 1 __ __ ___ _ __ ._ __ __ ___ . __ __ 1- __
2.2.N\ognet System
a .
Contact Trac ks
b. Measuring Potentiometer
c . Contact Pressure
d . Coil Resi sta n ce
e . Mechanical Friction
When themeasuring pot entiometer is w ithdrawn the fi ve screws A and the cover
can be removed.
The dust from the tef lon tubes B can be removed by means of a soft brush.
Clean the contact tracks C and the contact points with a soft cloth damped
w ith petrol.
The si lver lamellae on the potent i ometer should also be cleaned with petrol
and any metallic dust between the lomellae removed with a brush.
After considerab le w ear it may be desirable to re- grind the slider.D.
This is done by p la cing a piece of the finest glass-paper obtainab le between
the lamellae and the slider.
The potentiometer has been inserted and the writing system moved tocnd frose-
v eral times.
Then carefu ll y grind the edges of the s li der, al so by means of fine gl ass- paper
and remove an y grinding dust.
If the sl ider has been ben t , the contact pressure should be measured.
Place a piece of materia l, 0.7 mm th.ick, on the bottom pla te an d measure the
sl ider pressure at this distance from the bottom plate: 18 - 20 g.
Measure the resistance in the coi I s: Dri ve coi I: (E - F): approx. 2 kQ
Feed- bock""i l, (G -H), opp,ox. 1 kQ
Measure the force necessary to m ove the magnet syste m only
( re move the driving a rm from t he lug B): max. 60 g.
ATTENTION: Unde r no circumstances should oil be applied to the mag net system.
2 .3 . Replacement of the Slider.
2305.2 -1.67
Dismount locking spring by use of slim pliers and place t he new contact by
means of tweezers. Then the locking spring is put into position behindcontocts .
After
replacement re-grind the sli der as item 2.2 b .

BROEL & KJ.ER
Naarum -Denmark
Mechanical Section 2305.2
2.3. Gear Box -Motor
o. N\otor
b. N!agnetic Clutch
POWER:"Off"
MOTOR:"On"
PAPER DRIVE:"Start"
PAPER SPEED:"lOO mm/s" (large figure)
1:10 gear lever pushed in
c .!Tietion Clutch
POWER:" On"
MOTOR:" On"
PAPER DRIVE:"Start"
PAPER SPEED:"lOO mm/s" (large figure)
1 :1 0 gear I ever pushed in
d. Automatic stop
POWER:"On"
MOTOR:"On"
POTENTIOMETER RANGE:"Stand by"
WR ITING SPEED:"looo mm/s"
PAPER DRIVE:"Start -forward II
PAPER SPEED:"lO mm/s (smoll figure)
1:10 gear lever pulled out
e •.Lubricating
2305.2 - I .67
valid from serial no. 47978 sheet
2.
If necessary, loosen the four screws A and fix the motor in a position where it
runs smoothIy forward and backward.
Check that the distance between the clutch disc B and the clutch "mognet Cis
0.8 -1.0 mm.
If necessary loosen the screws D and move the clutch magnet to the correct
distance.
Switch on the POW ER and chec k that the ax le E starts andstops immediately
when switching MOTOR
DRIVE from nStop" to "Start" even if the grooved
finger wheel F
is blocked.
If necessary adjust the pressure of the clutch spring G.
Place a pin in the hale H in the grooved finger wheel F and check that the
friction clutch slips at a pressure of 150 g measured on the pin 10 cm from the
center.
If necessary adjust the pressure of the clutch spring bymeons of the nut 1.
When the
poperdrivehas stopped automatically draw a line across the paper by
moving the sapphire
from 0 to 50 dB.
Depress SINGLE
CHART for a short while and when the paper againstops auto-
matica ll y draw another line across the paper.
Switch PAPER DRIVE to "Reverse" and check that the paper drive stops at the
first line on the paper.
Tolerance: 0.5 mm
If necessary loosen the two screws K and adjust the screw l until the paper
drive stops at the same line for the motor running forward and backward.
Clean with petrol and lubricate the following ports with a non-ocidic machine
oil
(e.g. sewing machine oil:)
Warn and worm drive
All metal drive wheels
Moving parts for: 1:10
gear shift
Friction
clutch
The following ports are not oi led:
Axle bearings (self-lubricating)
i\\otor bearings (" )
tv\ognetic clutch
Nylon wheels
Pen lifting and marking relays