BRUEL & KJAER 2209 - Accelerometers

Velocity: 35 Hz- 5 kHz± 0.5 dB
25
Hz - 10 kHz ± 1.5 dB
Displacement:
50 Hz - 2 kHz± 0.5 dB
30 Hz - 4 kHz ± 1.5 dB
The temperature coefficients are:
Velocity+ 0.02 dBfOC
Displacement+ 0.04 dBfOC
Frequency response curves for the integrator and 2209 are shown in
Fig.6.15
and a circuit diagram in Fig.6. 16.
dB .--.~~~~--~~~~~~~~~----~~~~--~~~~
Acceleration
0
t=!jl]~~ --- -~~~~t=!jj!ttlli~tfttlmt=1jj1tlW
10 r--+-+~~~~~ -~- --=+-=-£~~~~~ : ~ .. ' . ~ . ~ .' .. --. +-~4+~~-+~+4~~--~~4+~
+---+--+...tii~~~ ··· ,_ ···· _,_,· ··· "F"'~d+-H'!.P..,....:.:: .. ;; ~:-~..-+--+-+~-I+---+---41ntegrator + 2209....._~-++++1-1
20
+---+-+V~~~ · + ·~ ~ · ·~--+~-+-+ · + ··· ~ · ~ - ~~~ - --+~- - -~~~~-H---+-~+
4
A
4
c+
1
ce~ler~om~e-te_r+-~-++++l-l
J ·- .. ~ 'I'-
/ ·- .. ~ 1
30
r--+-+
44
;+~--+-~4+~~-+. . ~~ ··,_. ~4+~~~-+-V~e
4
toc
4
iw~~--~~4+~
40
+---+~+++++++----_-Direct
I'\ "~
{
----1000 pF .._
r--+~++c• ++~~-+~++~~--~~~~--~~++~
......... 300 pF ~
50
+---+-+
44
~~--+-~4+~~-+~+4~~D-i~-l~ac-em~e~nt4+~~"-+~++~~
I'\ '!'-...
60 +---+-+44++~--+-~4+~~-+~+4~~~'\-+~+4~~--~~~~
70
BO
1 Hz 2 10 20
1'\.
50 100 200 500 1 kHz 2 5 10
Frequency Hz
f7;>oot
Fig.6. 15. Integrator frequency characteristics
6.2.4.
Accelerometers
The B & K range of accelerometers are of the piezoelectric compression
type. Sensitivities lie
within the range 1.2 mV /g to approx. 10 V /g (or the
range 0.4 pC/g- 10,000 pC/g) according to weight, configuration and
piezoelectric
material. In use with the 2209, the lower frequency limit of
measurement (within 2% of linear frequency response) is up to 25 kHz,
79