BRUEL & KJAER 2502 Operating instructions

BROEL & KJ..€R
N ce rum -Denmark
Consisting of:
Removal of the Case.
Serv i ce Instructi ons
Vibration Meter
Meter Circuit
Output Amplifier
Function Sele~tor
Position of Components
Parts List
Circuit Diagram
2502.1
2502.2
2502.3
2502.4
2502.5
2502.6
2502
After removing the four HEX/HD screws on the front panel, it is possible to slide the chassis and the front panel out of the rack or
the wooden case.
The metal case con be pulled out after the two screws on the bock panel hove been removed.
Block Diagram
Accelerot1on
Density~
Input Acc . Oens..
Alt
Function Meter
Selector Indication
l.F. Cut-Off Vibration
(Remote lewl {Remote Centro!.
Controt Potentiom.rters from generator)
Function
(R~Mnote Control Selector from
fromLL.ll) {RernoteControl
geMrator
from 441 1)
Trouble Shooting.
(-Control
from generator)
l DC
f Output
Control
S1gnol
Output
If the reason for a fault is not on obvious one such as a dead tube or transistor, broken down resistor, blown or disconnected fuse
etc., then first test the voltages of all the tubes and compare them with the voltages shown in the circuit diagram in order to loca-
lize the defect. Should this method of finding the fault prove unsuccessful, then check the instrument by adopting the method de-
scri bed in the adjustment procedure. When the troub le has been found and remedied, the voltages and adjustments which ore influ-
enced by the remedy must 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 cor-
rected without being sure that the tolerances of the instruments used for making the adjustment ore so small as to have no influence
on the measurements.
The instructions in this Manual ore given purely as a guide to the service of equipment with minor faults. Some faults, as f. inst.
small deviations in tolerances require for their correction special control equipment and extensive ex p erience, and in these cases it
is necessary to send the instrument to the factory.
Spore P orts.
P lease state type and seria l number of apparatus when spa re ports are ordered.
Instruments Necessary for Service and Repair:
F re q uency Analyzer type 21 07
( El ectronic Voltmeter type 2409)
Oscil l oscope
Bea t F requency Osci ll oscope type 1013
B eat F requency Osc il loscope type 101 7
F requency Counter
Mu l timeter (50 IJA)
2502 - 3.67

BROEL & KJJ£R
Ncerum - Denmark
1 .1 . Mechanical Zero-paint
METER TIME CONSTANT : "Off"
1. 2. Electrical Zero-paint
METER TIME CONSTANT: "1 sec."
1.3. Sensitivity
METER TIME CONSTANT: "1 sec."
1. 4. Ba l ance
METER TIME CONSTANT: "1 sec . "
2502 .1 - 3 .67
M . eter Circuit
2502.1
v alid from serial no. 172571
Adjust meter
scale for 0 .
Connect pin 7 of "Vibration Level Potentiometer" socket to ground .
Check that the painter is still at 0 .
Tolerance: Y2 painter "width" .
Vibration Level
Potentiometers
V 1 removed.
(00000)
2512
Frequency: 1000Hz. Adjust input signal for full scale deflection on type2502 .
Input voltage: Appro x. 9 V.
V 1
removed.
Frequency: 1000Hz. Adjust input vo ltage for full scale deflect ion on type
2502,
Measure the voltage across R 135 and R 1 36. Approx. : 9 V, max. di fference: 0. 3 dB.
(located on printed circuit XC 0258)
continued

1 .5 . Frequency Response
METER TIME CONSTANT: "1 sec."
1 .6. Overload
MEtER TIME CONSTANT: "!Osee . "
1.7. DCAmplifier
METER TIME CONSTANT: "1 sec."
1 .8. Meter Time Con.stdh.t
METER TIME CONSTANT: "30 sec. '1
l .9. Ripple
V 1 removed .
Frequency :
1000Hz. Adjust input vol tage foro 9,8 V deflection on type 2502.
Chec k the frequency response from 5 Hz to 100 kHz .
Tolerance: ± 0,2 V. (+ tolerance of type 1013, 1017:0 ,5 dB)
If necessary adjust P6 ot 100kHz . (locat ed on printed ci r cuit XC 0258)
V 1 removed.
Frequency: 1000Hz. Input voltoge:l2 dB abo ve full deflection on type 2502.
Chec k with an osci lloscope across R135 and R136 that the signal is not distort-
ed .
V 1
removed.
Frequency: 1000Hz. Adjust input voltage fdr full scale deflection on type
2502,
Measure the DC v oltage on "DC - Output" socket, pin 3:-6 .5 V.
Tolerance: ±2 % .
If necessary short-circuit C 47 to ground and adjust P7 for 0 Von "DC Out-
put" sockei, pin 3.
(C 47 is located on printed circuit XC 0258 arid P7 on XC 0226)
V 1 removed.
Frequency: 1000Hz . Adjust input voltage far a 10 V deflection on type 2502.
The meter time constant means the time it takes the meter pointer to fall from
10 V to 3,5 V when the input signal is disconnected.
in pcjslti~n "30 sec" the meier time constant should be 30 sec.
Cfieck METER tiME CONSTANT in position 0;3 -1-3-10 sec.
METER TIME CONSTANT: "Ali positions Vi re moved.
except0,3sec," Frequency: 1000Hz. Adjust input voltage far full scale deflection on type
2502,
MedSure the ripple on pin 3 of "DC Output" socket by me.:ms of voltmeter type
2409 .
tolerance : Max. 1 mV.
b .
METER TIME CONSTANT: "0,3 sec."
As item a .
Tolerance : Ma x. 5 mV.
2502 .1 - 3.67

BROEL & KJJER
Nc:srum - Denmark
Ou~put Amplifier
2502.2
2.1 . Sensiti vi ty
. ~ ,,
;0i
:•!· : ·: ~ ! - .: .~;~• ·
1013
(1017)
METER TlME CONSTANT: "1 sec."
FUNCTION SELECTOR: "Ext. Eilter"
v alid from ser ial no . 1 7257 1
1
o Ext
3 o J.O o 5 Fitter
6 0 0 7
2502
Frequenc y: 500 Hz . Adjust inp ut vo ltage foro 10 V deflection on ty pe 2502.
The input v oltage should be appro x . 10 mV.
1013 p 10
(1 01 7)
2.2. Acceleration Density
METER TIME CONSTANT: "1 sec . "
FUNCTION SELECTOR: "Ace. D en ."
ACCEL. DENS IT Y RANG E: "0,0 1"
2502.2 - 3. 67
Le 1e ~
Pote r1t1om eters
Input signa l: 100 mV, 500 Hz .
D eflection on type 2502: Full scale (<'0 dB)
If necessary adjust P 10
continued

2. 3. Frequenc y Res ponse
METER TIME CONSTANT:"! sec."
FUNCTION SELECTOR: "Ace. Den ."
ACCEL. DENSITY RANGE: "100"
ACCEL. DENSITY RANGE to "0,01"
2.4 . Overloading
FUNCTION SELECTOR: "Ace. Den."
2 .5 . ACOutput
FUNCTION SELECTOR: "Acc.Den . "
LEVEL BELOW CROSS-OVER: "0 "
ACCEL. DENSITY RANGE: "1 00 "
b. LE V EL BELOW CROSS-O V ER to "10"
LE V EL ABOVE CROSS-O V ER to "0"
d. LE V EL ABOVE CROSS-O V ER to "1 0"
2 .6. Noise and H um
FUNCTION SELECTOR: "Ace. D en."
ACCEL. DENSITY RANGE: "100"
2502.2 - 3 . 6/
Input signal: 10 V, 1 000 Hz.
Deflection on type 2502:100 g2 / cps
Check t he frequency response from 10 - 100.000 Hz.
Toler ance:± 2%
If ne cessa ry change v alue of C 79 (located on printed circuit XC 0258)
Input signal: 100 mV, 1000Hz.
Deflection on type 2502: l g2 / cps
Che ck the frequency re s ponse again::!:" 2 %.
If necessa ry adjust P 5 at 100kHz. (located on printed circuit XC 0258)
Input frequency: 1000Hz.
Connect on oscilloscope to "Vibration Level Potentiometer" socket pin 3, and
check that the signal is not distorted until12dB obove full scale deflection on
type 2502 .
Monitor
Frequency: 1000Hz. Adjust the input voltage for 10 Von "Vibration Level
Potentiometer" socket pin 3 .
The v
oltage on "Monitor" socket should be 10 V,
The output on "Control Signal Output" socket pin 1 should be max. 1 dB be-
low 10 V.
Output voltage on "Control Signal Output": 22-26 dB below 10 V
Connect a shorting link on "Cross-over" socket between pin 3 and 6 in order
to energize relay 0 16.
Output on "Cont rol Signal Output" socket pin 1 should be ma x. 1 dB below
10 v.
O ut put vol loge on "Control Signal Output": 22-26 dB belo w 10 V
The instrument must be in its case or in another w ay effectively screened.
Disconnect sign al in put and check noise and hum on "Vibration Le vel
P otentiometer" s ocke t pi n 3.
Max . 10 mV.

BRO EL & KJ.ER
Ncsrum -Denmark
. ~·:
:~:i:
.~~
=·!·:i:~!- ·'•~;~• :·
1022
3.1. Sensitivity Control
Function Selector
valid from serial no. 172571
1022
Ace. Gen.
Input
Relay Control Cross-over
1022- 2502
Relay Control
2502.3
2502--.1025 Relay Control B
· METER TIME CONSTANT: "1 sec . " The 2502's meter should read the v
alues given in the table (within 4% ) under
the stated conditions .
METER INDICATOR: "RMS"
Input to
ACC.GEN.
Relay Control
energized 1)
on pins
11
Accel.
11
g
11
Grad
11
gF
11
Vel.
11
in/sec.
11
Displ.
11
inches
11
Auto
11
D-A
11
Auto
11
V-A
11
Auto"
A-G
2502.3 - 3.67
It will be necessary to select suitable settings of the four RANGE selectors
according to the meter readings.
Readings in the 3 programmed "AUTO" positions of FUNCTION SELECTOR de-
pends on whether or not the cross-over rela ys are energized via pin 1 of "Relay
Control".
If a type 1008, 1019, 1025 or 1040-1042 is used, the "Relay Control" will be
energized automatically.
If a type 1022 {1 013 and 1017) is used, the - 6 V can be taken from pin 3
the "Crass-over" socket an type 2502.
10Hz
40Hz
125Hz 500Hz 2000Hz 8000 Hz
100 mV 100 mV
1V 1V 1V
1 v
52)
52) 52)
3 3 3
2 2 2
10 10 100 100
100
100
1,26 0,63 3,57 1,78 0,893 0,447
-
61,6 15,4
49,2
12,3 3,1
0,98 0 ,0613 0,0627 0,00392
-
-·~-
0,0627 100
in g - -
49,2 100
in/sec. g
100
3,57
g
gfs&.
Notes: 1) 6 V negative with respect to pin 4.
2) Energizing these pins should suppress low-frequency noise from the
generator but should not affect the sensitivity at the signal frequen-
cy.
If the sensitivities are w rong, make the following adjustments .
After
each adjustment check the values given in the table.
continued

3.2. Acceleration Sensitivity Adj.
ACCEL. RANGE: "100"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Acceleration"
b. METER INDICATION to "A.V. peak"
3.3. Displacement Sensitivity Adj.
DISPLACEMENT RANGE: "fJ.Ol"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Displacement"
b. METER INDICA Tl NG to "D peak-peak"
DISPLACEMENT RANGE to "1"
METER INDICATION to "RMS"
3.4. Rangex10
ACCEL. RANGE: "100"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Acceleration"
b. FUNCTION SELECTOR to "Auto"
ACCEL. RANGE to "10"
3.5. Noise and Hum
2502.3 - 3.67
Frequency: 500Hz. Adjust the input voltage to exactly 1 V.
It is recommended to use an electronic counter to monitor the test frequency.
Adjust P 3 for a 100 g deflection. (located on printed circuit XC 0258)
Adjust the input voltage for a 11 dB deflection on type 2502.
Adjust P 2 for a 20 dB deflection. (loco ted on printed circuit XC 0258)
Input frequency: 500Hz. Input voltage exactly 2.55 V.
Connect "Relay Control" pin 4 to ground and pin 5 to -6 Von "Cross-over"
pin 3 in order to energize 0 14 for a better low frequency stability.
Adjust P 4 (on ;>ri;1ted circuit XC 0258) for full scale deflection.
Adjust the input voltage for a 11 dB deflection on type 2502.
The deflection should now be 20 dB.
Remove connection to
11
Cross-over" socket pin 3.
Input frequency: 5Hz. Input voltage exactly 25.5 mV.
Adjust P 1 to 4% below full scale deflection.
Input signal: 1 V, 500 Hz
Deflection on type 2502: 20 dB.
Connect "Remote Function Selector" pin 4 to ground and pins 2 and 7 to -6 V
on "Cross-over" pin 3 in order to energize -Range x 10 Relay 0 1
Deflection on type 2502:20 dB.
Type 2502 must
be in its case or in other way effectively screened.
Measured on "Vibration Level Potentiometer" socket pin 3 in the frequency
range 20-40000 Hz .
Switches in all positions .
Max. noise and hum: 75 mV.

BROEL & KJJER
Ncerum -Denmark
+250V
6,3V "v
-6V
+ 250 v
C11
c 26
02
I
I
:.
Position of Components
val id from serial no. 172571
Control Signal
Output
pin 1 +250V
Vibration Level
Potentiometers
pin 2 pin 3 6,3VtV
C11
2502.4
I
I
I
.:
'-- --------- ~
-----~
Ground -6V Ext. Filter 0 27 0 26
XC 0258
2502.4 -3,67

025 025 025 025 025 025 -30V 6V pin3 C47 V17e
Ace. Density
Input
021
Ground
-6V
Ace. Gen.
Input
0 27
Ground
2502.4 - 3. 67
Ground
+ 250 v
6 V"V
c 11
C10
DC· XC 0258
Output
XC 0226
XC 0380
V11c Ground C5 Ground V11 b
~ - --1 - Ground
30 vrv
~~ ~(tQ ~ - 30V
R181. XC 0258
aa ;...._ --+-- - c10
'-- --- -+ -c 10
L..+- - - -- --- c10

BROEL & KJ..ER
2502.5
Ncerum - Denmark
Parts-List
vo .lid from serial no. 172571
CIRCUIT COMPONENT
STOCK CIRCUIT COMPONENT
STOCK
DIAGRAM
TYPE
REF. DIAGRAM TYPE
REF.
REF. REF.
CAPACITORS: R56 Carbon \3W 1% 191 kO
c 1-4 Electrolytic
640 1-1F/ 16 V
CE 0209 R57 127 kO
R 58
125 kO
C5
2 X 2000 ... FI 16 v
CE
0311
R59 75 kO
C6
320 1-1F / 64 V
CE 0511
R 60,61 100 kQ
C7
1 ~JF / 350 V
CE 0512 R
62
87 kO
ca 2 X 50
~JF/250 V
CE 0706 R
63
60 kO
C9
8 ~JF / 350 V
CE 0802
R64
50 kO
c 10,11 2x
50 ~JF / 450 V
CE 0909
R65
1 kO
C12
4 ~JF / 350 V
CE 0708 R
66,67 12,5 kO
c 13,14
4 ~JF/250 V
CE 2034 R 70
~ w 460 kO
c 15-250
1-1F / 10 V
CE 8944 R
71 Metal 2% 237
kQ
RF
0400
c 20 Ceramic 20
pF /400 V CK 0093 R·ao 2150 Q
RF 0401
c 21
12 pF/400 V CK 0095 R
81 Carbon V 3W 500 Q
c 30
Poly~~ter
33 nF/250 V
cs 0007 R
82 75 Q
c 31
0,1 IJF/250 V
cs
0013 R
83 60 kO
c 32,33
0,15 ~JF/250 V
cs 0015
R90 5%
lMO
c 34
0,22 ~JF/250 V
cs 0017 R
91,92
315 kO
c 35,36
0,33 ~JF/250 V
cs 0019 R
93,94
100 kO
c 37,38
0,47 fJF/250 V
cs 0021
R 96 18 kO
c 39-42
0,68 ~JF/250 V
cs 0023 R 98 40 kO
c 43-48
1 ~JF/250 V
cs 0025
R99
31,5 kO
c 49-72 2
~JF/250 V
cs 0028 R 100 10 kO
c 79 Polys,:yrene 400 pF/125 V CT 1011
R 101
20 kO
c 80 :1%62,6 nF/125 V CT 1100
c 81
11
6,26 nF/250 V CT 1203 R 102 3 kO
R 103
2,2 kO
c 82,83 9,9 nF/250 V CT 1204 R 104 3 kO
C84
19,8 nF/250 V CT 1206 R 105
1,6 kO
c 85 31,3 nF/250 V CT 1207
c 86
II
43,8 nF/250 V CT
1209 R 106 800 Q
c 87,88 89 nF/ 63 V CT 1500 R 108 315 Q
R 109 40 Q
c 89,90 110 nF/ 63 V CT
1501
R 110 360 Q
c 91
99 nF/ 63 V CT 1503 R 120-123
lO Yo 6,3MO
c 92 139
nF/ 63 V CT 1504 R 124,125
3,15MO
c 93
-t{),-1%
1 ~JF/100 V CT 5000
R126,127
2MO
c 94 2 IJF/100 V CT
5041
R128,129
lMO
RESISTORS:
R 130 630 kO
R 131 500 kQ
R 1 Carbon V
4W
RH 0002 R 132,133 100 kQ
R 2-3
V3w 0,5% . lMO
R 134 125 kO
R4 200 kO
Rl35,136 40 kO .
R5 111,1 kO R 137,138 10 kO
R 6-8
. 100 kO R 139 5% 40 kO
R9
45,6 kO R 140 10% 20 kO
RIO 20 kO R 141,142
6,3 kQ
R 11 11,11 kO R 143 5 kO
R 12-14 10 kO R 144,145
31,5 kO
R15 2 kO R 146
1,25 kO
R16 1,111 kO R 147 1 kQ
R 17,18
1 kO R 148 130 Q
R19 222,2
Q R 149 100 Q
R20,21 111,1 Q R 150 80 Q
R30 800 kO R 151,152 1 kO
R 31
200 kQ R 170,171 V2w 5
Yo 50 kO
R32 116 kO R 172 25 kO
R33 90,3 kO R 173
31,5 kO
R 34 80 kO R 174,175 150 Q
R 35 48,9 kQ R 180,181 10%
1,6MO
R36 41 kO R 182
lMO
R37 30,7 kO R 183 500 kO
R38 29 kO R 184,185 315 kO
R39 10,6 kQ R 186 250 kQ
R40 9,1 kO R 187 100 kO
R 41 6,03 kQ R 190-192
Wir 5,5W
15 kO RX 0304
R42
1,64 kO
R43 2 kO
R 50 % 1,11
MQ
R 51
300 kO
R52 266 kO
R53 320 kO
R54 250 kQ
R55 200
kO
2502.5 - 3.67

CIRCUIT
COMPONENT
DIAGRAM
TYPE
REF.
POTENTIOMETERS:
p 1
Trimmer carbon lin. 10 kO
p 2-4
wire 25 kO
p 5,6
carbon 100 kO
P7 150 kO
p 8,9
Cross-over
1. log. 100 kO
p 10
Trimmer wire lin. 1 kO
SWITCHES-RELAYS:
01-20 Mini Relay
021 Displ • Range
0 22 Velocity Range
0 23,24
Accel. Range- Accel. Grad. Range
0 25 Meter Time Constant
0 26 Meter Indication
Power on-off deck
0 27 Function Selector
0 28
Accel. Density Range
0 29 Mains Voltage Selector
RECTI Fl ERS:
Q 1-13
Silicon 200
V/0,04 A
Q 14 1200
V/0,15 A
Q
15-23
50 V/0,75 A
Q
24-27
1200 V/0,15 A
Q
28,29
65 V/ 0,6 A
Q 30..:34 Zener
6,8 V/0,05 A
Q
35,36
6,2 V/0,03 A
TRANSISTORS- TUBES:
v 1,2 Twin triode ECC82/12AU7
v 3-6
Pentode EF86/6
CF 8
V7 El86/6 CW 5
VB Stabilizer
082
v 9,10
Twin triode ECCBB/6 DJ 8
Vll
Germ. transistor 2N555
v 12 2N1613
v 13 BC107
v 14 BC107
v 15 BC107
v 16 2N4289
v 17 2N3440
v 18 Fuse
1,6A
v 19 2,5 A
v 20-26
Ind. lamp
V27 Meter lamp 6,3 V/0,5 A
v 28,29 Cross-over ind. 6,3 V/0,15 A
PRINTED CIRCUITS:
DC- Amplifier
Input-Output Amplifier
Power Supply
Input Attenuators
XC 0226 with components
XC 0258 "
XC 0259
XC 0380
MISCELLANEOUS:
2502.5 - 3.67
Bakelite knob 25 mm
Cabinet, wood
, metal
Power Cord, EUR
" I USA
transformer
Socket Relay 0 15, 16
" " 0 1-14, 17-20
Tube V 8
v 1-7, 9, 10
Monitor Output Jack
Glass Cover for Indication lamp
STOCK
REF.
PG
3\02
PG 3251
PG 4102
PG
4151
pp
4111
PQ
2100
oc 0006
OR 2502
OS 2502
OT 2502
ou 2502
ov 2502
ox 2502
OY 2502
JS 0005
QV 0022
QV 0025
QV 0501
QV 0025
QV 1003
QV 1106
QV 1307
VA 0011
VA 0019
VA 0024
VA 0040
VA 0073
VB 0023
VB 0026
VB 0257
VB 0032
VB 0257
VB 0049
VB 0250
VF 0007
VF 0011
vs 0008
vs 1271
vs 8008
XC 0226
XC 0258
XC 0259
XC 0380
8032502
8002502
8022502
8012502
SN
0701
KA 0016
KQ 0047
AN 0005
AN 0006
TN 0012
JJ 0008
JJ 0012
JV 7505
JV 9012
JJ 1006
SG 0328
CIRCUIT
COMPONENT STOCK
DIAGRAM
TYPE REF.
REF .

BROEL & KJ.ER
Ncerum - Denmark
1.1 . lv\echonicol Zero-point
METER TIME CONSTANT: "Off"
1. 2. Electrical Zero-point
METER TIME CONSTANT :"! sec."
1.3. Sensitivity
METER TIME CONSTANT: "1 sec."
1 .4. Balance
METER TIME CONSTANT:"! sec."
2502.1-8.67
Meter Circuit
2502.1
valid from serial no. 201566
Adjust meter scale for 0.
Connect pin 7 of "Vibration Level Potentiometer" socket to ground .
Check that the pointer is still at 0.
Tolerance: V2 pointer "width".
Possible reason for fault: Defective V 2
Vibration Level
Potentiometers
V 1 removed.
-- - ~1.~ ..
( 00000)
2502
Frequency: 1000Hz. Adjust input signal for full scale deflection on type2502.
Input voltage: Approx. 9 V.
V 1
removed.
Frequency: 1000Hz. Adjust input voltage for full scale deflection on type
2502,
lv\eosure the voltage across R 135 and R 136. Approx.: 9 V,mox. difference: 0.3 dB.
(located on printed circuit XC 03970
continued

1. 5. Frequency Response
METER TIME CONSTANT: "1 sec."
1 .6. Overload
METER TIME CONSTANT: "!O s ee . "
1.7. DC Amplifier
METER TIME CONSTANT: "1 sec . "
1.8 . Meter Time Constant
METER TIME CONSTANT: "30 sec."
1.9 . Ripple
V 1 removed.
Frequency: 1000 Hz. Adjust input v
oltage for a 9,8 V deflection on type 2502.
Check the frequency response from 5 Hz to 100 kHz .
Tolerance:± 0,2 V. {+tolerance of type 1013, 1017:0,5 dB)
If necessary adjust P6 at 100kHz . {located on printed circuit XC 0397)
V 1 removed.
Frequency:
1000Hz. Input v oltage:l2 dB above full deflection on type 2502.
Check with an oscilloscope across R135 and R136
that the signal is not distort-
ed.
V 1 removed.
Frequency:
1000Hz. Adjust input voltage for full scale deflection on type
2502,
Measure the DC v oltage on "DC Output" socket, pin 3: -6 .5 V.
Tolerance:
±2 %.
If necessary short-circuit C 47 to ground and adjust P 7 for 0 Von "DC Out-
put" socket, pin 3.
{C 47 is located on printed ci rcuit XC 0397 and P 7 on XC 0226)
V 1 removed.
Frequency:
1000Hz . Adjust input v oltage for a 10 V deflection on type 2502.
The meter time constant means the time it takes the meter pointer to fall from
10 V to 3,5 V when the input signal is disconnected.
In position"30 sec" the meter time constant should be 30 sec.
Check METER TIME CONSTANT in position 0,3- 1 -3- 10 sec.
METER TIME CONSTANT: "All positions V 1 removed.
except0,3sec." Frequency: 1000Hz. Adjust input voltage for full s cale deflection on type
2502,
Measure the ripple on pin 3 of "DC Output" socket by means of voltmeter type
2409.
Tolerance: Max. 1 mV.
b. METER TIME CONSTANT: "0,3sec."
As item a.
Tolerance: Ma x. 5 mV.
2502 0 1 - 80 67

BROEL & KJ...£R
Ncsrum -Denmark Output Amplifier
2502.2
2. 1. Sensitivity
METER TIME CONSTANT: "1 sec."
FUNCTION SELECTOR: "Ext . Filt er"
:ei
;• : ! ·: ~: ~ !- : i ~ ! ~ · :·
1013
(1017)
2.2. Acceleration Density
METER TIME CONSTANT: "1 sec ."
FUNCTION SE LECT OR : "Ace. Den."
ACCE L. DENSITY RANG E: "0,01"
2502 .2 - 3. 67
va lid
from serial no. 1725 71
10
3 o l.O o s Fi lter
6 0 0 7
2 50 2
Frequency: 500Hz. Adjust input voltage for a 10 V deflection on type 2502.
The input vo ltage should be opprox . 10 mV.
p 10 2 50 2
Le 1et
Potent1ometers
In put signal: 100 mV, 500 Hz.
Meter
Deflection on type 2502: Full scale (iOd B)
If necessary adjust P 10
continu ed

2. 3. Frequency Response
METER TIME CONSTANT:"] sec."
FUNCTION SELECTOR: "Ace . Den."
ACCEL. DENSITY RANGE: "100"
ACCEL. DENSITY RANGE to "0,01"
2.4. Overloading
FUNCTION SELECTOR: "Ace. Den."
2.5 . AC Output
FUNCTION SELECTOR: "Acc .Den . "
LEVEL BELOW CROSS-OVER: "0"
ACCEL. DENSITY RANGE: "100"
b. LEVEL BELOW CROSS-OVER to "1 0"
LEVEL ABOVE CROSS-OVER to "0"
d . LEVEL ABOVE CROSS-OVER to "10"
2.6. Noise and Hum
FUNCTION SELECTOR:"Acc. Den . "
ACCEL. DENSITY RANGE: "100"
2502.2 - 8.67
Input signal: 10 V, 1000Hz.
Deflection on type 2502: 100 g2/cps
Check the frequency response from 10- 100.000 Hz.
Tolerance:± 2%
If necessary change value of C 79 (located on printed circuit XC 0397)
Input
signal: 100 mV, 1000Hz.
Deflection on type 2502: 1 g2/cps
Check the frequency response again:~ 2 %.
If necessar y adjust P 5 at 100kHz . (located on printed circuit XC 0397)
Input
frequency: 1000 Hz .
Connect on oscilloscope to "Vibration Level Potentiometer" socket pin 3, and
check that the signal is not distorted until12dB above full scale deflection on
type 2502.
Monitor
Frequency: 1000Hz. Adjust the input voltage for 10 Von "Vibration Level
Potentiometer" socket pin 3 .
The
voltage on "Monitor" socket should be 10 V.
The output on "Control Signal Output" socket pin 1 should be max . 1 dB be-
low 10 V.
Output voltage on "Control Signal Output": 22-26 dB below 10 V
Connect a shorting link on "Cross-over" socket between pin 3 and 6 in order
to
energize relay 0 16.
Output on "Control Signal Output" socket pin 1 should be max. 1 dB below
10 V.
Output voltage on "Control Signal Output": 22-26 dB below 10 V
The instrument must be in its case or in another way effectively screened.
Disconnect signal input and check noise ond hum on "Vibration Level
Potentiometer" socket pin 3 .
Max . 10 mV.

BROEL & KJ..ER
Ncerum - Denmark
·~~
:~~z
.~ · ~ ·
;j:!· : i:~!- ·' •!~• ·
1022
3.1. Sensitivity Control
Function Selector
valid from serial no . 201566
1022
Ace. Gen.
Input
2502.3
sheet 1
Relay Control Cros!H!Ver Relay Control 1025-2502
Relay Control B
1022-2502
METER TIME CONSTANT: "1 sec ."
METER .INDICATOR: "RMS"
The 2502's meter should read the values given in the table (within 4%} under
the stated conditions.
Input to
ACC.GEN.
Relay Control
energized 1)
on pins
11
Accel.
11
g
"Grad
11
gF
"Vel."
in / sec.
"Displ."
inches
11
Auto
11
D-A
11
Auto
11
V-A
11
Auto
11
A-G
2 502.3 - 8.67
It will be necessary to select suitable settings of the four RANGE selectors
according to the meter readings.
Readings in the 3 programmed "AUTO" positions of FUNCTION
SELECTOR de-
pends on whether or not the cross-over relays are energized via pin 1 of "Relay
Control".
If a type 1008, 1019, 1025 or 1040-1042 is used,the stabilizing relays will be
energized automatically.
If a type 1022 (1 013 and 1017} is used, the - 6 V can be taken from pin 3
the "Cross-over" socket on type 2502.
10Hz
40Hz
125Hz 500Hz 2000Hz
8000Hz
100mV 100 mV
1V
1V 1V 1 v
2) 2)
52) 52) 52)
3 3 3 3
2 2 2 2 2
10 10 100 100 100 100
1,26 0,63 3,57 1,78 0,893
0,447
61,6 15,4
49,2
12,3 3,1
0,98 0,0613
0,0627 0,00392
0,0627 100
in
g
49,2
100
in/sec.
g
100
3,57
g
g'fs&.
Notes: 1} 6 V negative with respect to pin 4.
2) Energizing these pins should suppress low-frequency noise from the
generator but should not
affect the sensitivity at the signal frequen-
cy.
If the sensitivities are wrong, make the following adjustments.
After
each adjustment check the values given in the table .
continued

R41
01
02
3.2. Displacement Sensitiv ity Adj.
DISPLACEMENT RANGE: "0,01"
METER TIME CONSTANT: "1 sec . "
METER INDICATION : "D peak-peak"
FUNCTION SELECTOR: "Displ."
b. DISPLACEMENT RANGE to "1"
3.3. Velocity Sensitivity Adj.
a. VELOCITY RANGE: "1"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "A. V.- peak"
FUNCTION SELECTOR: "Vel."
b. METER INDICATION to "RMS"
DISPLACEMENT RANGE
ta "0,01"
FUNCTION SELECTOR to "Displ."
3.4. Acceleration Sensitivity Adj.
ACCELERATION RANGE: "1"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Accel."
2502.3 - 8.67
P2 Pl P4 Integrating Low-froq. Output
n~:·,~
fl- B- fi 1HHt fi
010 08
012-14 011
Cathode
Follower Miller lntegrator
lndicat1ng
Meter
It is recommended to use an electronic counter to monitor the test frequencies.
Input frequenc y: 500Hz . Input voltage: Exactly 0,9 V.
Connect "Relay Control" pin 4 to ground and pin 5 to -6 V on "Cro s s-o v er"
pin 3 in order to energize 0 14 for better low -frequenc y stability .
Adjust P 3 for 20 dB deflection on type 2502.
Input frequency: 5Hz . Input voltage: Exactly 9 mV.
Adjust P 1 for 4%
belo w full scale deflection.
Input frequency: 500Hz. Input voltage: Exactly 57.4 mV.
Adjust P
11 for 20 dB deflection an type 2502.
Adjust P 2 far a defi P. ctian of 17 dB.
Input frequency: 500Hz. Input voltage: Exactly 0,9 V.
Adjust P 4 for 11 dB deflection on type 2502.
Input frequenc y: 500Hz. Input v oltage: Exactly 10 mV.
Adjust P 12 for 20
dB deflection on type 2502.

BROEL & KJkR
NCErum - Denmark
AcceLGen.
Input
3.5. Acceleration Gradient Sensitivity Adj.
ACC. RADIENT RANGE: "0.01"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Grad."
3.6. Range x 10
ACCEL. RANGE: "100"
METER TIME CONSTANT: "1 sec."
METER INDICATION: "RMS"
FUNCTION SELECTOR: "Acceleration"
b. FUNOION SELECTOR to "Auto"
ACCEL. RANGE to "10"
3.7. Noise and Hum
2502.3 - 8. 67
Fun~tion Selector
2502.3
v alid from serial no. 201566
Input
frequency: 500Hz. Input voltage: Exactly 5.6 mV.
Adjust P 13 for 20 dB deflection.
Input signal: 1 V, 500Hz.
Deflection on type 2502: 20 dB.
sheet 2
Connect "Remote Function Selector" pin 4 to ground and pins 2 and 7 to -6 V
on "Cross-over" pin 3 in order to energize 0 1, 0 5 and 0 8.
Deflection on type 2502: 20 dB.
Type 2502 must be in its
case or in other way effectively screened.
Measured on "Vibration Level Potentiometer" socket pin 3 in the frequency
range
20-40000 Hz •
Switches in all positions.
lvlo x . noise and hum: 75 mV.