SPX Cooling Technologies TG MAG86-100 Manual Do Utilizador
17
A.0500.551 – IM-TGMAG/02.00 EN (02/2008)
The values depend on the position from where one measures and were therefore
measured at the front of the pump, at distance of 1 meter from the pump cover and
were corrected for background noise and reflections.
measured at the front of the pump, at distance of 1 meter from the pump cover and
were corrected for background noise and reflections.
The values listed are the highest measured values under following operating conditions.
• working pressure: up to 10 bar.
• pumped medium: water, viscosity = 1 mPa.s
• —% n
max
= — % maximum shaft speed
TG MAG pump size
n
max
(min-1)
Lpa (dB(A))
Ls (dB(A))
25% n
max
50%n
max
75%n
max
100%n
max
15-50
1500
61
72
79
83
9
23-65
1500
63
75
81
85
10
58-80
1050
67
79
85
89
10
86-100
960
69
80
86
90
11
185-125
750
71
82
87
91
11
Sound power level (L
WA
)
The sound power L
W
is the power emitted by the pump as sound waves and is used to compare
sound levels of machines. It is the sound pressure Lp that acts on a surrounding surface at distance
of 1 meter.
of 1 meter.
L
WA
= L
pA
+ Ls
The A-weighted sound power level L
WA
is also expressed in decibels dB(A).
The reference sound power is 1 pW (= 10
-12
W). L
S
is the logarithm of the surrounding surface at
distance of 1 metre from the pump, expressed in dB(A) and is listed in the last column of the table
above.
above.
3.7.2 The sound level of the pump unit
The sound level of the drive (motor, transmission,…) must be added to the sound level of the pump
itself to determine the total sound level of the pump unit. The sum of several sound levels must be
calculated logarithmically.
itself to determine the total sound level of the pump unit. The sum of several sound levels must be
calculated logarithmically.
For a quick determination of the total sound level the following table can be used:
L
1
–L
2
0
1
2
3
4
5
6
L[f(L
1
–L
2
)]
3.0
2.5
2.0 1.7 1.4 1.2 1.0
L
total
= L
1
+ L
corrected
where
L
total
: the total sound level of the pump unit
L
1
: the highest sound level
L
2
: the lowest sound level
L
corrected
: term, depending on the difference between both sound levels
For more than two values this method can be repeated.
Example:
Drive unit
: L
1
= 79 dB(A)
Pump
: L
2
= 75 dB(A)
Correction
: L
1
- L
2
= 4 dB(A)
According to the table : L
corrected
= 1.4 dB(A)
L
total
= 79 + 1.4 = 80.4 dB(A)