469-P5-HI-A20-E
469-P5-HI-A20-E
B網(wǎng)絡(luò)是模擬人耳對70 phon純音的響應(yīng),它使電信號通過時,低頻段有一定的衰減。
C網(wǎng)絡(luò)是模擬人耳對l00phon純音的響應(yīng),在整個聲頻范圍內(nèi)有近乎平直的響應(yīng),它讓所有頻率的電信號幾乎一樣程度地通過,所以C網(wǎng)絡(luò)可以代表聲頻范圍內(nèi)的總聲級。
實際上,A. B, C網(wǎng)絡(luò),分別相當(dāng)于40,70,100phon等響曲線的倒立形狀。
脈沖精密聲級計(如國產(chǎn)ND6型和丹表(B/K)2209型精密聲級計)又設(shè)置了D網(wǎng)絡(luò),用來評價飛機噪聲。
經(jīng)過頗率計權(quán)網(wǎng)絡(luò)側(cè)得的聲壓級特別稱作為聲級,根據(jù)所使用的計權(quán)網(wǎng)絡(luò)不同,分為A 聲級(LA), B聲級(LB)和C聲級(Lc),記作dB(A), dB(B), dB(C)。表7-4及圖7-13說明了三種計權(quán)網(wǎng)絡(luò)的頻率特性。
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ALLEN BRADLEY 1761-NET-ENI SERIES B EXTERNAL INTERFACE FRN.:2.00
JAN FAN JF110VHEM
DESTACO FL-161/60 STRAIGHT-LINE ACTION CLAMPS FLANGE MT, 2000 LBS CAP.
DESTACO FO-161/60 VARI. STROKE STRAIGHT-LINE PLUNGER CLAMPS, FOOT MT.
DESTACO 82L2G-2430000B POWER CLAMPS BASE MODEL WITHOUT HANDLE, ENCL.
BANNER MSXLR4824Y MINI SCREEN MIN OBJECT SENS: 1.00 IN (25.4MM)
BALDOR M35A013T589G1 MOTOR
DESTACO 82G6N-632E402-02090A-P PNEUMATIC POWER CLAMP W/1020 CLAMP ARM
NORGREN EC90-A-1-X49A-90A-L-30-10 PNEUMATIC POWER CLAMP EC SERIES
NORGREN EC90G-6-0-0-0-0-0-0-D-30-10 PNEUMATIC POWER CLAMP EC SERIES
NORGREN EC90G-6-0-0-0-0-GCA114M-3-R-30-10 PNEUMATIC POWER CLAMP
NORGREN EC90G-6-0-0-GCA15M-3-0-0-D-90-10 PNEUMATIC POWER CLAMP
NORGREN EC90G-6-0-0-0-0-GCA172M-2-R-90-10 PNEUMATIC POWER CLAMP
PHD SLB82X40-AE-AR-DB-J8-M-Q1-UB15 SLIDE, 20PSI MIN. TO 150PSI MAX
STI 40344-0010
ALLEN BRADLEY 281D-F12Z-10C-CRW ARMORSTART CONTROL MODULE CONTROL VOLT, SEE DESC
EMCOR 1503-4-4057 BALL SCREW ASSEMBLY OVERALL LENGTH 23-1/2"
TREGASKISS TR-2150 V-BLOCK CLEANING TIP .85/.938/1.2062/1.106
AMCI 1531 RESOLVER INTERFACE PLC MODULE FOR ALLEN BRADLEY SLC500
INA T500202-609 R/T LINEAR GUIDE RAIL 1127MM 21 HOLE 2 SLIDERS
EFECTOR LK3124 LK0728A-A-00KLPKG/US LEVEL SENSOR / SWITCH,
GORBEL 77157 COIL CABLE
SMC NCDA1B400-1970-XC22 CYLINDER SMC NCDA1B400-1970-XC22,
SIEMENS 6ES7-158-0AD01-0XA0 SIMATIC S7 COUPLING MODULE DP/DP COUPLER
KENNEDY 24"X25"X31-1/2" 5 DRAWER TOOL CABINET, GRAY
KENNEDY 24"X25"X31-1/2" 7 DRAWER TOOL CABINET GRAY
VIATRAN 345APGX1126
RELIANCE ELECTRIC 1SU41002
BARBER COLMAN CB41-01120-025-5-00
HONEYWELL DC5300-100-P-10-0-E000-0
ACDC ELECTRONICS RSF502B-2300-0065
DAIHEN FDA-B03