上海鉑固原裝進(jìn)口歐洲工控產(chǎn)品 超快物流 特價(jià)供應(yīng)
聯(lián)系人:王藝皓
手機(jī):15102181261
Q Q:523314469
優(yōu)勢供應(yīng)Sera 90006226 Antriebsmembrane PTFE-k d78 WP318917膜片
優(yōu)勢供應(yīng)Sensortechnics SQ:97598 -14.7to+10psig
優(yōu)勢供應(yīng)Sera 16007164 R409.2-50e UV隔膜泵
優(yōu)勢供應(yīng)Sera 90000320壓力油口（壓力閥內(nèi)）
優(yōu)勢供應(yīng)Sera RF409.2-140e 16016327隔膜泵
優(yōu)勢供應(yīng)Sera 30058008 SL-02塑料管接頭
優(yōu)勢供應(yīng)Sera SUCTION VALVE FOR R409.1-150E
優(yōu)勢供應(yīng)Sera SERA R410.2-450E隔膜泵
優(yōu)勢供應(yīng)Sera 90022678 Connection rod Schubstange d12 l=71,6 WP351489
優(yōu)勢供應(yīng)Sera 90000267吸氣閥口（吸氣閥內(nèi)）
優(yōu)勢供應(yīng)Sensormatic srl OGSL-220-PUK-ST3光電傳感器
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE2-1000熱電偶
優(yōu)勢供應(yīng)SENSTRONIC FPV 1 KD 2Y 5G 6A 3D AA516
優(yōu)勢供應(yīng)SENSY 5000M-1"3/4
優(yōu)勢供應(yīng)Sera 90000018球閥（壓力閥內(nèi)）
優(yōu)勢供應(yīng)Sera R409.2-18e UV隔膜泵
優(yōu)勢供應(yīng)sensus Sensus 243-12-6 Regulator, Pressure, DN 50, Flanged, PN16 Raised Face, Spring: 30-70 mbar (Orange), Orifice: 3/4 inch, with OPSO, Valve Assembly: 30 Degrees
優(yōu)勢供應(yīng)SensoTec IHG 100 art.no.044 - 11290 ( standard),incl. - Helix cable手輪
優(yōu)勢供應(yīng)Sensormatic srl OGSL-220-PUK-ST3 (10KHz-220-100)
優(yōu)勢供應(yīng)Sera connecting rod fur C409.2-140E WP351489
優(yōu)勢供應(yīng)Sera R410.2-570E
優(yōu)勢供應(yīng)sensus DN40 / QN 10， 4Q1103 221， 420 040L300G2 Q10BETO，42EEXCFNHVHS2XXXXXE
優(yōu)勢供應(yīng)SENSTRONIC A126325m120211
優(yōu)勢供應(yīng)SENSTRONIC FPG 1 KE 2Y 5G 6A 3D AA516
優(yōu)勢供應(yīng)SENSTRONIC A1202S5Q261021
優(yōu)勢供應(yīng)SENSTRONIC FPA 1 KJ 2Y 5G 6A 3D AA516
優(yōu)勢供應(yīng)SENSTRONIC L128V/3MLC15TS電纜
優(yōu)勢供應(yīng)sensus DN25 / QN 6， 4Q1103 211， 420 025L260G11/2 Q6BETO， 42ECXCENHHHS2XXLXXE
優(yōu)勢供應(yīng)Sera MPD-340 PP Hytrel+PTFE泵
優(yōu)勢供應(yīng)Sera connecting rod fur C410.2-510E WP342358
優(yōu)勢供應(yīng)Sensortechnics 003-0421-900
優(yōu)勢供應(yīng)SENSTRONIC A 1202S5-Q261021(U_26X26)
優(yōu)勢供應(yīng)sensus 50101 C323G D1A1X
優(yōu)勢供應(yīng)Sera 90000244閥冠（吸氣閥內(nèi)）
優(yōu)勢供應(yīng)SensoTec BL114DL, 6H, 30A 07512948
優(yōu)勢供應(yīng)Sera R410.2-900e隔膜泵
優(yōu)勢供應(yīng)Sensortechnics CTEM8350GY4V 0-350mbarg,4-20mA,G1/8",FKM（不帶插頭和線纜）
優(yōu)勢供應(yīng)SENSY 5300-100T-SL稱重傳感器
優(yōu)勢供應(yīng)SensoTec 060-H032-03
優(yōu)勢供應(yīng)Sera Repair kits for R409.1-150E
優(yōu)勢供應(yīng)SENSTRONIC A126305M181011
優(yōu)勢供應(yīng)Sensortechnics CTE8001GY0V
優(yōu)勢供應(yīng)Sera 90006227 Antriebsmembrane PTFE-k d64 WP318932膜片
優(yōu)勢供應(yīng)sensus MS008108 Besblcode MEISTREAM 50401DKI1DBCA1X Produktausführung MS, Wasserz?hler kpl. Zulassungskennzeichen 2004/22/EG (MID) Modul H1 Nennweite DN DN 80 Nenndurchfluss Q3 = 63 m3/h metrol. Kl. / Verh?ltnis Q3/Q1 R63 Druckstufe PN 16 Baul?nge 225 mm Bohrbild EN 1092 PN16 Materialspezifikation Standard (KTW, W270) Composite Z?hlwerk mechanisch, HRI-Mei+OD vorber. Anzeige m3 Zusatzhinweis mit Str?mungsgleichrichter
優(yōu)勢供應(yīng)SENSTRONIC FPG 1 KG 2Y 5G 6A 3D AA516
優(yōu)勢供應(yīng)SensoTec Type： K insulation PTFE,Dimensions2.4mm（round） cable length 4m mini plug type：male
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE4-1500熱電偶
優(yōu)勢供應(yīng)Sensortechnics HCEMI00GUH9P3
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE4-1200熱電偶
優(yōu)勢供應(yīng)SensoTec Class1, type:K PTFE Dimensions 2,3mm(round) cable length 4 m, mini plug type:male green
優(yōu)勢供應(yīng)SENSTRONIC S27/13
優(yōu)勢供應(yīng)sensus MS-65；50401CII3GD1A1X
優(yōu)勢供應(yīng)Sera 90006227Antriebsmembrane PTFE-k d64膜片
優(yōu)勢供應(yīng)Sensortechnics CTEM70350GY7壓力傳感器
優(yōu)勢供應(yīng)Sensortechnics TE7N01GY4感應(yīng)傳感器
優(yōu)勢供應(yīng)SENSY SEN SY5950 2T,16mA
優(yōu)勢供應(yīng)Sensortechnics CTEM7P750GY4-X壓力傳感器
優(yōu)勢供應(yīng)Sera MEMBRANE FOR TYPE R411.1-280
優(yōu)勢供應(yīng)SENSTRONIC REP65/50055H24D
優(yōu)勢供應(yīng)Sera R410.2-570E No.wp337836
優(yōu)勢供應(yīng)Sera R409.2-18E 316231DS172P21隔膜泵
優(yōu)勢供應(yīng)SENSTRONIC REP8DES23B進(jìn)口模塊
優(yōu)勢供應(yīng)SENSTRONIC A1263P5M1202 10-30VDC 200mA PNP NO Sn2.5mm
優(yōu)勢供應(yīng)SensoTec AY321HT
優(yōu)勢供應(yīng)Sensortechnics sq273-p001gz8p壓力開關(guān)
優(yōu)勢供應(yīng)Sensortechnics RMOP030GTMH D/C 0714壓力傳感器
優(yōu)勢供應(yīng)Sensortechnics sq274-10326 dc04/13bxxx 370031-xxxx
優(yōu)勢供應(yīng)SENSTRONIC REP6550055SC28
優(yōu)勢供應(yīng)SENSTRONIC SDPL08/PL
優(yōu)勢供應(yīng)SENSY COND-SGA-D-V2信號(hào)放大器
優(yōu)勢供應(yīng)Sera SL-02 PVC-U PTFE Kab-frei加料管
優(yōu)勢供應(yīng)SENSTRONIC REP45 / 50055SC28 (26 4-pin socket)
優(yōu)勢供應(yīng)Sera MBM78-18CFW for C409.2-115e
優(yōu)勢供應(yīng)Sensortechnics BTEL5P10D4A
優(yōu)勢供應(yīng)Sera 16009637 - C409.2-140e
優(yōu)勢供應(yīng)SENSTRONIC 液壓閥 離合軟制動(dòng)傳感器A1302P2M120111
優(yōu)勢供應(yīng)Sera APB-650 PP Santo+PTFE隔膜泵
優(yōu)勢供應(yīng)Sera type:R411.1-280 Nr.256987
優(yōu)勢供應(yīng)SENSTRONIC A1202N6L12SP11TS接近開關(guān)
優(yōu)勢供應(yīng)SENSTRONIC A126305M180851K_DC24V
優(yōu)勢供應(yīng)SENSTRONIC C1263P2Q050311 DC24V
優(yōu)勢供應(yīng)SENSTRONIC A120216Q401521
優(yōu)勢供應(yīng)SENSTRONIC PROLGANT4R8120接口模塊
優(yōu)勢供應(yīng)SENSY CARD-CDL10接口模塊
優(yōu)勢供應(yīng)Sera 90000018 POS21/0球閥（吸氣閥內(nèi)）
優(yōu)勢供應(yīng)SensoTec 060-3146-02
優(yōu)勢供應(yīng)SENZANI MOTA.I80B65/21 0.55KW,400V,900rpm NO.193852
優(yōu)勢供應(yīng)Sensortechnics SQ219-12328
優(yōu)勢供應(yīng)Sera C409.2-75e
優(yōu)勢供應(yīng)SENSTRONIC A120212L181011KTK
優(yōu)勢供應(yīng)Sensortechnics HCEMI00GUH9P3 DCI5/I5DBXXX 490174-XXX
優(yōu)勢供應(yīng)Sera C409.
優(yōu)勢供應(yīng)Sera 90006228 PTFE-k d44密封件
優(yōu)勢供應(yīng)Sera R409.2-18E隔膜泵
優(yōu)勢供應(yīng)Sera RF409.2-140e/0-140L/HX 0.37KW
優(yōu)勢供應(yīng)SENSTRONIC A 120216-Q401521
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE4-900熱電偶
優(yōu)勢供應(yīng)Sensortechnics RMOH004DTMH D/C 4310
優(yōu)勢供應(yīng)SENSORIK FSP 30-6S 20-04
優(yōu)勢供應(yīng)Sensortechnics BTE2025G1A，0-25bar
優(yōu)勢供應(yīng)SensoTec CA301BJ, 6AZ, 7B, 33A
優(yōu)勢供應(yīng)SENSTRONIC REP45/50055SC28
優(yōu)勢供應(yīng)Sera R410.2-200E
優(yōu)勢供應(yīng)Sensortechnics GTE8001AY4V 4-20MA G1/8 Male ,FKM 0-350mbar
優(yōu)勢供應(yīng)SENSY 5900-CMIJ
優(yōu)勢供應(yīng)SensoTec ITEM NO: M-00095-02 060-8247-29
優(yōu)勢供應(yīng)Sera 90000304壓座（壓力閥內(nèi)）
優(yōu)勢供應(yīng)Sera PTFE-k d174膜片
優(yōu)勢供應(yīng)sensus 243-12 IRV
優(yōu)勢供應(yīng)sensus DN20 / QN 2,5， 4Q1103 201， 420 020L190G1 Q2,5BETO，42EBXCCNHCHS2XXXXXE
優(yōu)勢供應(yīng)SENSY DISP-PAXP負(fù)荷限制器
優(yōu)勢供應(yīng)Sera 90022678 Connection rod Schubstange d=25 l=112,5
優(yōu)勢供應(yīng)Sensortechnics CTE7N01GY4壓力傳感器
優(yōu)勢供應(yīng)sensus KMBAD1I1, 10 liter / pulse
優(yōu)勢供應(yīng)Sensortechnics ID:CTE8001AY4V;7...32V;4...20mA;0...1bara;DIC 3815
優(yōu)勢供應(yīng)Sera RF409.2-75e
優(yōu)勢供應(yīng)sensus Sensus 243-12-6 Regulator, Pressure, DN50, Flanged, PN16 Raised Face, Spring: 30-70 mbar (Orange), Orifice: 3/4 inch, with OPSO, Valve Assembly: 30 Degrees
優(yōu)勢供應(yīng)SENSTRONIC SDPL18/PL
優(yōu)勢供應(yīng)SENSTRONIC A 1202S5-Q261021
優(yōu)勢供應(yīng)sensus TYP：MeiStream100； 13118963 please see the picture attached
優(yōu)勢供應(yīng)Sera 90003218O型圈（壓力閥內(nèi)）
優(yōu)勢供應(yīng)SENSTRONIC A1263CCL150111
優(yōu)勢供應(yīng)Sera 90003222O型圈（壓力閥內(nèi)）
優(yōu)勢供應(yīng)sensus MS-80 MeiStream DN80 Besblcode MEISTREAM 50401DKI1ABCA1X流量計(jì)
優(yōu)勢供應(yīng)SENSTRONIC |PROXIMITYSWITCH|A1302P2M120111接近開關(guān)
優(yōu)勢供應(yīng)SENSTRONIC Z000377198
優(yōu)勢供應(yīng)SENZANI SVE552100 P/N40600111油壓傳動(dòng)閥
優(yōu)勢供應(yīng)Sera R412SoRry Nr.206816
優(yōu)勢供應(yīng)SENSTRONIC T12/5MLP315TS電纜
優(yōu)勢供應(yīng)Sensortechnics SQ274P005GUN8CS DC16/11 BXXX 183770-xxxx
優(yōu)勢供應(yīng)Sera R409.2-140e隔膜泵
優(yōu)勢供應(yīng)Sera RF410.2-900e隔膜泵
優(yōu)勢供應(yīng)Sensortechnics RPOM050D6A壓力傳感器
優(yōu)勢供應(yīng)Sera 37600706 622.10 1.4581 PTFE-k SN：5122056減壓閥
優(yōu)勢供應(yīng)Sera R409.2-115E S330199
優(yōu)勢供應(yīng)SENSY Typ DKA 26 see the picture
優(yōu)勢供應(yīng)Sera RF409.2-140e/0-140l0.37kw/Sera WP327969
優(yōu)勢供應(yīng)Sera R409.2-115e柱塞泵
優(yōu)勢供應(yīng)SENSTRONIC REP8DES23B SEM 25/2011 Pn:65148
優(yōu)勢供應(yīng)Sera 723.1 DN20;37601002減壓閥
優(yōu)勢供應(yīng)sensus 046， 1““NPT， MWN part #， 121-1045K， 57 SCFM natural gas， 228psig inlet， 100 psig outletSPRING: 122-1435 TAN 50-125 psig、ORIFICE: 122-1260 orifice 3/16“
優(yōu)勢供應(yīng)SENSTRONIC L12/4T
優(yōu)勢供應(yīng)sensus WP-Dynamic 50
優(yōu)勢供應(yīng)Sera C409.2-50e MBE-02隔膜泵
優(yōu)勢供應(yīng)SensoTec AP121BN, 1A, 2J, 3D, 5B, 6A, 14A
優(yōu)勢供應(yīng)Sera 90005258 POS24/ 0O型圈(吸氣閥內(nèi))
優(yōu)勢供應(yīng)Sera Outlet valve FOR R409.1-150E
優(yōu)勢供應(yīng)Sera 90006226 Antriebsmembrane PTFE-k d78 WP318989膜片
優(yōu)勢供應(yīng)SENSORIK FSP 30-6-E-20-04-SS
優(yōu)勢供應(yīng)sensus Regulator, Pressure, DN50, Flanged, PN16 Raised Face, Spring: 30-70 mbar (Orange), Orifice: 3/4 inch, with OPSO, Valve Assembly: 30 Degrees, Sensus 243-12-6
優(yōu)勢供應(yīng)SensoTec WTM AR
優(yōu)勢供應(yīng)SensoTec DA-05 Nr.060-6881-03
優(yōu)勢供應(yīng)SENSTRONIC A1202F5Q804021
優(yōu)勢供應(yīng)Sera 623.D DN20;36231101油壓傳動(dòng)閥
優(yōu)勢供應(yīng)sensus PRESSURE REGULATING VALVE: Part No. model:121-12 of DWELT HEATER JR2500-H/1.6-Q HEATER. N:08103315 TS2210407-2010, TYPE:STD,SPRING:1.5-3PSi,ORIF:STD,CONN:2-1/2"SCRD
優(yōu)勢供應(yīng)SENSTRONIC REP8DES23L接口模塊
優(yōu)勢供應(yīng)Sera R409.2-350e
優(yōu)勢供應(yīng)SENSTRONIC A120216P404021
優(yōu)勢供應(yīng)Sensortechnics CTEM70350GY4壓力傳感器
優(yōu)勢供應(yīng)SENSTRONIC A 10216-Q401521(U_40X40)
優(yōu)勢供應(yīng)Sera TYP:DRF409.1-190E NR.WP308406
優(yōu)勢供應(yīng)sensus 4Q1103201 – DN20
優(yōu)勢供應(yīng)Sera BJ04010293 RF409.2-75e
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE5-1200熱電偶
優(yōu)勢供應(yīng)SENSORIK fsp 30-6e-20-04-ss
優(yōu)勢供應(yīng)SENSTRONIC A1202B6L 160111M DC24V
優(yōu)勢供應(yīng)Sera typ:r 409.1-380 e nr.284227
優(yōu)勢供應(yīng)SENSORIK FSP 30-6E 22-04 SS
優(yōu)勢供應(yīng)sensus 046， 1“NPT， MWN part #， 121-1045K， 57 SCFM natural gas， 100 psiginlet， 15 psig outlet、SPRING: 122-1420 aluminum 8-20 psig、ORIFICE:122-1260 orifice 3/16“
優(yōu)勢供應(yīng)sensus MEISTREAM 80 temperature：30 °C PN 16 Qn 40m3/h metr.KI.B 100069501
優(yōu)勢供應(yīng)Sera R409.2-140e MATERIAL: PP
優(yōu)勢供應(yīng)Sera 16013158 R410.2-280e üV隔膜泵
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE1-347熱電偶
優(yōu)勢供應(yīng)SENSTRONIC A126302L080271KTKIPS L08
優(yōu)勢供應(yīng)Sera R409.2-12e NO.316231DS172P21
優(yōu)勢供應(yīng)Sera 90005258O型圈(壓力閥內(nèi))
優(yōu)勢供應(yīng)SensoTec 060-3150-02 SN：251897
優(yōu)勢供應(yīng)Sera C 409.2-250e隔膜泵
優(yōu)勢供應(yīng)Sensortechnics CTE8001AY4V 0-1bara,4-20mA,G1/8"male,FKM
優(yōu)勢供應(yīng)Sera B74706 APB-340
優(yōu)勢供應(yīng)Sera 90011436 Antriebsmembrane PTFE-k d138,5膜片
優(yōu)勢供應(yīng)SENSTRONIC A120212L181011K
優(yōu)勢供應(yīng)SENSTRONIC A126302L080271KTK
優(yōu)勢供應(yīng)Sensortechnics SQ:97853 -14.7to+15psig
優(yōu)勢供應(yīng)SENSTRONIC C1263P2Q050311
優(yōu)勢供應(yīng)Sensortechnics RMOH010DTMH D/C 4510
優(yōu)勢供應(yīng)sensus MEISTREAM 80水表
優(yōu)勢供應(yīng)Sera TYPE:C409.2-50eNr:wp309130QN0-50l/hp1min/max-0.3/0barnN100l/minp2max10bar隔膜泵
優(yōu)勢供應(yīng)SENSTRONIC REP65/50055H24S
優(yōu)勢供應(yīng)SENSORIK fsp 30-28-02-ev1
優(yōu)勢供應(yīng)SENSTRONIC SDPQ05RTP
優(yōu)勢供應(yīng)Sera TYPE:C409.2-75e Nr:wp309139隔膜泵
優(yōu)勢供應(yīng)Sera 627.D 1.4581 PTFE-k減壓閥
優(yōu)勢供應(yīng)Sera 90009396 FLP2泵
優(yōu)勢供應(yīng)Sera 8184 DN25;30082013油壓傳動(dòng)閥
優(yōu)勢供應(yīng)Sera 90003222 POS22/ 0O型圈（吸氣閥內(nèi)）
優(yōu)勢供應(yīng)Sensortechnics SQ274-10280 183894
優(yōu)勢供應(yīng)sensus 243-12-1，1-1/2“NPT with 1-2“ psi spring. 3/8“ orifice size and10 degree valve
優(yōu)勢供應(yīng)SENSTRONIC SDPQ05RS
優(yōu)勢供應(yīng)SENSTRONIC A126301Q530141
優(yōu)勢供應(yīng)SENSORIK FSP 30-6S 20-04 SS
優(yōu)勢供應(yīng)SensoTec BL113DR, 31B, 6H, 30A 07513948
優(yōu)勢供應(yīng)SensoTec AN-VEO-TP1-375熱電偶
優(yōu)勢供應(yīng)Sera 409.2-18eUV計(jì)量泵
優(yōu)勢供應(yīng)SENSY 2712-20daN信號(hào)放大器
優(yōu)勢供應(yīng)SENSTRONIC A1302P2M120111感應(yīng)傳感器
優(yōu)勢供應(yīng)Sera RF409.2-140e
優(yōu)勢供應(yīng)SENSTRONIC C126302Q050311
優(yōu)勢供應(yīng)Sera R409.2-12e1
優(yōu)勢供應(yīng)SENSTRONIC A126305K50A/65 DC24V
優(yōu)勢供應(yīng)SensoTec AN-VEO-TP5-40熱電偶
優(yōu)勢供應(yīng)sensus DN50 PN1630-70MBA3 / 4 INCH OPSO 30 Level 243-12-6
優(yōu)勢供應(yīng)SENSY WT R-IZ 63754
優(yōu)勢供應(yīng)Sera 15002623 - C409.2-115e üV
優(yōu)勢供應(yīng)Sera 754.1 DN25;37601248過濾器
優(yōu)勢供應(yīng)SENSTRONIC SHUNTCODP
優(yōu)勢供應(yīng)SENSTRONIC L12/4L21H接近開關(guān)
優(yōu)勢供應(yīng)Sera 90006227 Antriebsmembrane PTFE-k d64膜片
優(yōu)勢供應(yīng)SensoTec AN-VEO-TE1-375熱電偶
優(yōu)勢供應(yīng)SENSY MODEL：2600 CAP:75t OUTPUT 2mV/V Breaking Load：300% Maximum operating load：150% Accuracy class：0.25 Cable length：12m Protection：IP67雙剪切梁式稱重傳感器
優(yōu)勢供應(yīng)Sensortechnics CTE8N05GY0N-X壓力傳感器
優(yōu)勢供應(yīng)Sera 90008822 HVP1 DN8泵
優(yōu)勢供應(yīng)Sera SERA R409.2-140e UeV泵
優(yōu)勢供應(yīng)SENSY DISP-BOYP
優(yōu)勢供應(yīng)Sera WP314612
優(yōu)勢供應(yīng)SENSTRONIC A120216Q404021
優(yōu)勢供應(yīng)SENSTRONIC A126305K500/65 DC24V
優(yōu)勢供應(yīng)Sensortechnics RMOP030ATMH壓力傳感器
優(yōu)勢供應(yīng)SENSTRONIC SDPM14C-LG25
優(yōu)勢供應(yīng)SENSORIK FSP30-6-E-22-04（includes Adapter20038）
優(yōu)勢供應(yīng)SENSTRONIC A126305M080211 with 2M cable
優(yōu)勢供應(yīng)SENSTRONIC A126305M080211（2m cable with plug）
優(yōu)勢供應(yīng)Sera 8003 DN20;30040005球閥
優(yōu)勢供應(yīng)Sera 206 816
優(yōu)勢供應(yīng)Sera C409.2-350E SN:WP351498
優(yōu)勢供應(yīng)Sensortechnics KTU65K0G0
優(yōu)勢供應(yīng)Sera D100PU Typ : C409.2-350e UEV MBE-02泵
優(yōu)勢供應(yīng)SENSTRONIC L12/5MLLDT
優(yōu)勢供應(yīng)SensoTec AL131CV,1A,2U,6E,15C
優(yōu)勢供應(yīng)Sera 8004;DN25;30041005球閥
優(yōu)勢供應(yīng)Sera APB-340 PP Hytrel+PTFE
優(yōu)勢供應(yīng)SensoTec Typ K Kl. 1 ?2,0mm NL= 575mm inkl. Thermoleitung FEP/CU-Schirm/FEP L= 2000m熱電偶
