一、標準三相電機 | |||
全閉外扇形SF-JR/SF-TH/SF-JRO/SF-THO//SF-JRV/SF-TV/SF-JRVO/SF-TVO//SF-JRF/SF-JRFO 型號表示 | |||
防滴保護形SB-JR/SB-TH/SB-JRV/SB-JRF/SB-LV 型號表示 | |||
•標準式樣 *標準式樣(番號63~225) *標準式樣(番號250~280) | |||
•特性 *全閉外扇形 *防滴保護形 | |||
•尺寸及質(zhì)量 | |||
1,全閉外扇形 | |||
*SF-JR(0.1~0.4KW) *SF-JR(0.4~55KW) *SF-TH(55~132KW) | |||
*SF-JRF(0.1~0.4KW) *SF-JRF(0.4~45KW) | |||
*SF-JRV(0.1~0.4KW) *SF-JRV(0.4~30KW) | |||
2,防滴保護形 | |||
*SB-JR(0.4~30KW) *SB-JR(22~90KW) *SB-TH(90~200KW) | |||
*SB-JRF(0.4~55KW) | |||
*SB-JRV(0.4~30KW) *SB-JRV(22~90KW) *SB-LV(55~132KW) |
沖擊電流Iimp12.5KA浪涌保護器-UP2.5KV電源防雷器
應用于電源供電系統(tǒng)第一級的防雷保護產(chǎn)品。產(chǎn)品具備很高的雷電流泄放能力,單模塊最大放電電流達到100kA,可防范直擊雷在內(nèi)的各種電涌。應用于雷擊風險較高地區(qū)的設備系統(tǒng)的電源第一級防雷。
一級電源浪涌保護器無續(xù)流,可以安裝在電度表前面作浪涌保護。產(chǎn)品為標準 35mm 導軌式安裝方式,每模塊占兩位標準安裝位置。通過不同數(shù)量的組合可適用于單、三相電源系統(tǒng)。
Iimp=15ka(10/350),Up≤2.5kV間隙式防雷模塊,具有高雷電通流能力,適用于電源系統(tǒng)第一級防雷保護。該產(chǎn)品廣泛用于移動通信基站、微波通信局/站、電信機房、工業(yè)廠礦、民航、金融、證券等電源系統(tǒng),如各種配電站、配電房、配電柜、交直流配電屏、開關箱以及其它各種重要且易遭受雷擊的設備。
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| |
SPD端口 | 一端口 | |
SPD類別 | 限壓型 | |
額定電壓Un | 220/380VAC | |
最大持續(xù)運行電壓Uc | 385VAC | |
沖擊電流(10/350)Iimp | 電流峰值Ipeak | 50kA |
電荷量 Q | 25As | |
能量 W/R | 625kJ/Q | |
標稱放電電流(8/20)In | 60kA | |
最大放電電流(8/20)Imax | 100kA | |
電壓保護水平Up | ≤2.2kV | |
響應時間tA | ≤25ns | |
前置熔斷器 | 125AgG | |
連接導線 | 16-35mm2 | |
安裝 | 35mm標準導軌(EN50022/DIN46277-3) | |
工作環(huán)境溫度 | -40℃~+85℃ | |
外殼材料 | 符合UL94V-0 | |
外殼保護等級 | IP20 |
周先生聯(lián)系:15152706676 QQ:1303869585
機器性能:
Cu2+ | Zn2+) | Fe3+ | Al3+ | Ni+ | Cr+ | K+ | Pb+ | Cl- | NO-2 | NO-3 | SO2-4 |
0.001 | 0.002 | 0.002 | 0.003 | 0.001 | 0.001 | 0.002 | 0.003 | 0.01 | 0.02 | 0.01 | 0.02 |
2711P-T7C15A22711P-K4M20A2711P-K4M20D2711P-K4M3A2711P-K4M3D2711P-K4M5A2711P-K4M5D2711P-B6C1A2711P-B6C1D2711P-B6C20A2711P-B6C20D2711P-B6C3A2711P-B6C3D2711P-B6C5A2711P-B6C5D2711P-B6C8A2711P-B6C8D2711P-B6M1A2711P-B6M1D2711P-B6M20A2711P-B6M20D2711P-B6M3A2711P-B6M3D2711P-B6M5A2711P-B6M5D2711P-B6M8A2711P-B6M8D2711P-K6C1A2711P-K6C1D2711P-K6C20A2711P-K6C20D2711P-K6C3A2711P-K6C3D2711P-K6C5A2711P-K6C5D2711P-K6C8A2711P-K6C8D2711P-K6M1A2711P-K6M1D2711P-K6M20A2711P-K6M20D2711P-K6M3A2711P-K6M3D2711P-K6M5A2711P-K6M5D2711P-K6M8A2711P-K6M8D2711P-T6C1A2711P-T6C1D2711P-T6C20A2711P-T6C20D2711P-T6C3A2711P-T6C3D2711P-T6C5A2711P-T6C5D2711P-T6C8A2711P-T6C8D2711P-T6M1A2711P-T6M1D2711P-T6M20A2711P-T6M20D2711P-T6M3A2711P-T6M3D2711P-T6M5A2711P-T6M5D2711P-T6M8A2711P-T6M8D2711P-B7C15A12711P-B7C15A22711P-B7C15B12711P-B7C15B22711P-B7C15D12711P-B7C15D22711P-B7C4A12711P-B7C4A22711P-B7C4B12711P-B7C4B22711P-B7C4D12711P-B7C4D22711P-B7C6A12711P-B7C6A22711P-B7C6B12711P-B7C6B22711P-B7C6D12711P-B7C6D22711P-K7C15A12711P-K7C15A22711P-K7C15B12711P-K7C15B22711P-K7C15D12711P-K7C15D22711P-K7C4A12711P-K7C4A22711P-K7C4B12711P-K7C4B22711P-K7C4D12711P-K7C4D22711P-K7C6A12711P-K7C6A22711P-K7C6B12711P-K7C6B22711P-K7C6D12711P-K7C6D22711P-T7C15A12711P-T7C15B12711P-T7C15B22711P-T7C15D12711P-T7C15D22711P-T7C4A12711P-T7C4A22711P-T7C4B12711P-T7C4B22711P-T7C4D12711P-T7C4D22711P-T7C6A12711P-T7C6A22711P-T7C6B12711P-T7C6B22711P-T7C6D12711P-T7C6D22711P-B10C15A12711P-B10C15A22711P-B10C15B12711P-B10C15B22711P-B10C15D12711P-B10C15D22711P-B10C4A12711P-B10C4A22711P-B10C4B12711P-B10C4D12711P-B10C4D22711P-B10C6A12711P-B10C6A22711P-B10C6B12711P-B10C6B22711P-B10C6D12711P-B10C6D22711P-K10C15A12711P-K10C15A22711P-K10C15B12711P-K10C15B22711P-K10C15D12711P-K10C4A22711P-K10C4B12711P-K10C4B22711P-K10C4D12711P-K10C4D22711P-K10C6A12711P-K10C6A22711P-K10C6B12711P-K10C6B22711P-K10C6D12711P-K10C6D22711P-T10C15A12711P-T10C15A22711P-T10C15B12711P-T10C15B22711P-T10C15D12711P-T10C15D22711P-T10C4A12711P-T10C4A22711P-T10C4B12711P-T10C4B22711P-T10C4D12711P-T10C4D22711P-T10C6A12711P-T10C6A22711P-T10C6B12711P-T10C6B22711P-T10C6D12711P-T10C6D22711P-B12C15A12711P-B12C15A22711P-B12C15B12711P-B12C15B22711P-B12C15D12711P-B12C15D22711P-B12C4A12711P-B12C4A22711P-B12C4B12711P-B12C4B22711P-B12C4D12711P-B12C4D22711P-B12C6A12711P-B12C6A22711P-B12C6B12711P-B12C6B22711P-B12C6D12711P-B12C6D22711P-K10C4A12711P-K12C15A12711P-K12C15A22711P-K12C15B12711P-K12C15B22711P-K12C15D12711P-K12C15D22711P-K12C4A12711P-K12C4A22711P-K12C4B12711P-K12C4B22711P-K12C4D12711P-K12C4D22711P-K12C6A12711P-K12C6A22711P-K12C6B12711P-K12C6B22711P-K12C6D12711P-K12C6D22711P-T12C15A12711P-T12C15A22711P-T12C15B12711P-T12C15B22711P-T12C15D12711P-T12C15D22711P-T12C4A12711P-T12C4A22711P-T12C4B12711P-T12C4B22711P-T12C4D12711P-T12C4D22711P-T12C4D2K2711P-T12C6A12711P-T12C6A22711P-T12C6B12711P-T12C6B22711P-T12C6D12711P-T12C6D22711P-B15C15A12711P-B15C15A22711P-B15C15B12711P-B15C15B22711P-B15C15D12711P-B15C15D22711P-B15C4A12711P-B15C4A22711P-B15C4B12711P-B15C4B22711P-B15C4D12711P-B15C4D22711P-B15C6A12711P-B15C6A22711P-B15C6B12711P-B15C6B22711P-B15C6D12711P-B15C6D22711P-K15C15A12711P-K15C15A22711P-K15C15B12711P-K15C15B22711P-K15C15D12711P-K15C15D22711P-K15C4A12711P-K15C4A22711P-K15C4B12711P-K15C4B22711P-K15C4D12711P-K15C4D22711P-K15C6A12711P-K15C6A22711P-K15C6B12711P-K15C6B22711P-K15C6D12711P-K15C6D22711P-T15C15A12711P-T15C15A22711P-T15C15B12711P-T15C15B22711P-T15C15D12711P-T15C15D22711P-T15C4A12711P-T15C4A22711P-T15C4B12711P-T15C4B22711P-T15C4D12711P-T15C4D22711P-T15C6A12711P-T15C6A22711P-T15C6B12711P-T15C6B22711P-T15C6D12711P-T15C6D22711-PRN10C2711P-RDB10C2711P-RDB12C2711P-RDB15C2711P-RDB7C2711P-RDK10C2711P-RDK12C2711P-RDK15C2711P-RDK7C2711P-RDT10C2711P-RDT12C2711P-RDT12CK2711P-RDT12H2711P-RDT15C2711P-RDT7C2711P-RDT7CK2711P-RN12711P-RN10H2711P-RN15C2711P-RN15S2711P-RN22C2711P-RN32711P-RN62711P-RN82711P-RP2711P-RP12711P-RP1A2711P-RP22711P-RP2A2711P-RP2K2711P-RP32711P-RP3A2711P-RPA2711-K3A10L12711-K3A17L12711-K3A2L12711-K3A5L12711-M3A18L12711-M3A19L12711-B5A12711-B5A102711-B5A10L12711-B5A10L22711-B5A10L32711-B5A152711-B5A15L12711-B5A15L22711-B5A162711-B5A16L12711-B5A1L12711-B5A1L22711-B5A1L32711-B5A22711-B5A202711-B5A20L12711-B5A2L12711-B5A2L22711-B5A2L32711-B5A32711-B5A3L12711-B5A3L22711-B5A3L32711-B5A52711-B5A5L12711-B5A5L22711-B5A5L32711-B5A82711-B5A8L12711-B5A8L22711-B5A8L32711-B5A92711-B5A9L12711-B5A9L22711-B5A9L32711-K5A12711-K5A102711-K5A10L12711-K5A10L22711-K5A10L32711-K5A152711-K5A15L12711-K5A15L22711-K5A15L32711-K5A162711-K5A16L12711-K5A1L12711-K5A1L22711-K5A1L32711-K5A22711-K5A202711-K5A20L12711-K5A2L12711-K5A2L22711-K5A2L32711-K5A32711-K5A3L12711-K5A3L22711-K5A3L32711-K5A52711-K5A5L12711-K5A5L22711-K5A5L32711-K5A82711-K5A8L12711-K5A8L22711-K5A8L32711-K5A92711-K5A9L12711-K5A9L22711-K5A9L32711-T5A10L12711-T5A15L12711-T5A16L12711-T5A1L12711-T5A20L12711-T5A2L12711-T5A3L12711-T5A5L12711-T5A8L12711-T5A9L12711-B6C12711-B6C102711-B6C10L12711-B6C152711-B6C15L12711-B6C162711-B6C16L12711-B6C1L12711-B6C22711-B6C202711-B6C20L12711-B6C2L12711-B6C32711-B6C3L12711-B6C52711-B6C5L12711-B6C82711-B6C8L12711-B6C92711-B6C9L12711-K6C12711-K6C102711-K6C10L12711-K6C152711-K6C15L12711-K6C162711-K6C16L12711-K6C1L12711-K6C22711-K6C202711-K6C20L12711-K6C2L12711-K6C32711-K6C3L12711-K6C52711-K6C5L12711-K6C82711-K6C8L12711-K6C92711-K6C9L12711-T6C10L12711-T6C15L12711-T6C16L12711-T6C1L12711-T6C20L12711-T6C2L12711-T6C3L12711-T6C5L12711-T6C8L12711-T6C9L12711-K10C12711-K10C102711-K10C10L12711-K10C152711-K10C15L12711-K10C162711-K10C16L12711-K10C1L12711-K10C202711-K10C20L12711-K10C32711-K10C3L12711-K10C82711-K10C8L12711-K10C92711-K10C9L12711-K10G12711-K10G102711-K10G10L12711-K10G152711-K10G15L12711-K10G162711-K10G16L12711-K10G1L12711-K10G202711-K10G20L12711-K10G32711-K10G3L12711-K10G82711-K10G8L12711-K10G92711-K10G9L12711-T10C12711-T10C102711-T10C10L12711-T10C152711-T10C15L12711-T10C162711-T10C16L12711-T10C1L12711-T10C202711-T10C20L12711-T10C32711-T10C3L12711-T10C82711-T10C8L12711-T10C92711-T10C9L12711-T10G12711-T10G102711-T10G10L12711-T10G152711-T10G15L12711-T10G162711-T10G16L12711-T10G1L12711-T10G202711-T10G20L12711-T10G32711-T10G3L12711-T10G82711-T10G8L12711-T10G92711-T10G9L12711E-K10C152711E-K10C62711E-T10C152711E-T10C62711-ND32711E-ND12711E-ND72711-CF2M2711-CK2M2711-CK3M2711-CT10C2711-CT3M2711-CT6C2711-CT6M2711-CRJ4222711-CCBLUU022711-CRCSD2711-NP12711E-UK12EK102711E-UKCK102711E-UT12ET102711E-UTCT102711E-UK14EK102711E-UT14ET102706-P22R2706-P42C2706-P42R2706-P44C2706-P44R2706-P72CN12706-P72CN22706-P74CN12706-P74CN22706-P92C2706-P94C2706-PCNETK2706-PCNETM2706-PCNETP2706-PDH485K2706-PDH485M2706-PDH485P2706-PDHPK2706-PDHPM2706-PDHPP2706-PDNETK2706-PDNETM2706-PDNETP2706-PENET12706-PENETK2706-PENETM2706-PENETP2706-PRIOK2706-PRIOM2706-PRIOP2706-PSW12706-NE19701-VWSTMDEE9701-VWSTMENE9701-VWSTMFRE9701-VWSTMJPE2711-NMCC2711-NC212711-NL12711-NC132711-NL32711-NL52711-NL42711-NM132711-NM2322711P-RY20322711P-RTMC2711P-RCH 2711PRCH2711P-RW22711P-RC42711PT12C4D62711PT12C4D72711PT15C15A7
產(chǎn)品品牌 | 西門子Siemens | 產(chǎn)品型號 | 6ES7138-4CA01-0AA0 |
使用于 | ET200S系列 | 寬度 | 15mm |
電壓類別 | 24V直流 | 尺寸 | 81x15x52mm |
輸出類型 | 電流/電勢/電壓 | 深度 | 52mm |
長度 | 81mm |
PAL制式電視信號發(fā)生器簡介
PAL制式電視信號發(fā)生器是多功能電視信號發(fā)生器,具有音頻,視頻信號輸出的多制式電視信號發(fā)生
器.是一款電視信號發(fā)生器電路結(jié)構緊湊的高質(zhì)量產(chǎn)品。包括C01,C08,C16,C18,C28多種型號?刹糠痔娲M口產(chǎn)品Fluke54000系列,GV798和GV898,GV698、GV698+,PM5418,TSG 271,PM5518
,CG-935P(PAL),Chroma2326。TG35CX,TG19CC,LEADER 408NPS
特點:■ 電視制式支持: PAL, NTSC, SECAM*, PAL-M*, PAL-N*, NTSC-4.43* 等全球不同制式;■ 視頻輸出信號包括:復合視頻,Y/C分量,YCbCr分量,RGB*■ 視頻輸出接口包括:BNC,S端子,SCART*■ 左右聲道同時輸出1KHz,400Hz音頻信號■ 十余種測試信號包括P卡(飛利浦測試卡)和復合測試圖信號可用于評價彩色電視機多項功能和特
性,包括顏色,幾何,線性,會聚,頻率響應等■ 按鍵直選,操作簡捷■ 可根據(jù)用戶要求定制專用測試信號
規(guī)格:(標準配置)彩色制式: NTSC,PAL,SECAM,PAL-M;
視頻:復合視頻: 極性: 正 輸出幅度: 1Vp-p±50mVp-p 輸出阻抗: 75Ω 輸出接口: 1BNC,SCART*
Y/C分量: 極性: 正 輸出幅度: Y 1Vp-p±50mVp-p , C 620mVp-p±20mVp-p 輸出阻抗: 75Ω 輸出接口: S端
YCbCr分量: 極性: 正 輸出幅度: Y 1Vp-p±50mVp-p Cb,Cr 522mVp-p±20mVp-p 輸出阻抗: 75Ω 輸出接口: 3BNC RGB分量: 極性: 正 輸出幅度: 0.7Vp-p±50mVp-p
輸出阻抗: 75Ω 輸出接口: SCART
音頻: 信號頻率: 1 KHz±50Hz,400Hz±20Hz,10Hz-20KHz掃頻信號 輸出幅度: 1Vp-p±20mVp-p 輸出阻抗: 1KΩ 輸出接口: 2BNC,SCART*
圖像: 彩條,EIA彩條,格子,點格,黑白格,窗口,灰階,單色場,圓, 復合測試圖,飛利浦卡測試圖,清晰度測試卡,獅子頭
電源要求: AC 220V±10% 50Hz/60Hz操作環(huán)境: 室內(nèi)操作尺寸和重量: 426mm(寬)X300mm(深)X6.6mm(高) 7.5Kg
有* 號為選裝
BATERSUARG(倍特雙)全自動犬排卵測定儀
產(chǎn)品說明:
倍特雙犬排卵檢測儀是通過檢測動物陰道黏液的電阻變化判斷犬是否處于排卵發(fā)情期。
能夠規(guī)避肉眼觀察的誤差,又可避免錯過動物最佳交配時間,杜絕獸醫(yī)成本的支出和浪費。
技術參數(shù):
測試速度:2秒鐘內(nèi)
測試方法:一次測試
重 量: 約0.3公斤。
電力供應: 1電池9伏,類型6f22
顯 示: 3位,液晶顯示器
測量范圍: 0 -1 990個單位
工作溫度: 0 -7 0° C時
濕 度: 85 %
使用建議:
目前,我們針對國內(nèi)多個品種的母犬在發(fā)情期所檢測數(shù)據(jù)的分析與總結(jié),對全自動犬發(fā)情排卵測定儀的說明書進行了重新編寫,請直接按照說明指導進行操作即可,在每一臺排卵儀的工具箱里并配有一張A4紙,上面有使用方法的重點介紹。
當然不可避免的是,您或許在操作過程中還是會出現(xiàn)這樣或那樣的問題,那么請您隨時致電我們。我們會給出詳細解答。
溫馨提示:母犬的炎癥、疾病、及其公犬精子質(zhì)量,甚至于有些飲食方法的因素會對受孕率造成一些影響,請您在這幾個方面多注意。
使用步驟:
1、在空氣中檢測一下儀器是否有電,空氣中檢測顯示屏上會出現(xiàn)“10”。
2、測量前請注意母犬外陰保持清潔;
3、按照說明書中步驟將儀器的探桿和探頭進行充分清洗,等同于消毒。
4、分開母犬的外陰,小心的插入探針直至達到宮頸口處,
5、打開測定儀。
6、待顯示屏顯示出數(shù)字后讀取結(jié)果。
7、取出探針。
8、按照消毒說明消毒探針。
建議初次使用者在測量前做如下練習:
1、對發(fā)情明顯的牲畜進行測試。
2、對未發(fā)情期的牲畜進行測試。
GD-LDC/Q潛水型電磁流量計,集國外電磁流量計的優(yōu)點,并根據(jù)國內(nèi)的實際使用情況而設計?梢杂脕頊y量酸,堿,鹽等腐蝕性液體或液體內(nèi)混有固體的兩相體,如礦漿,泥漿和含有大量雜物的污水及粘度很大的介質(zhì)。在化工,冶金,造紙、制藥、制糖、輕紡、釀酒、食品、環(huán)保、化纖、水利,油田注聚等行業(yè)獲得廣泛應用。
工作原理: 潛水型電磁流量計是根據(jù)法拉弟電磁感應定律設計的,在測量管軸線和磁場磁力線相互垂直的管壁上安裝一對檢測電極,當導電液體沿測量管在交變磁場中,磁力線成垂直方向運動時,導電液體切割磁力線產(chǎn)生感應電勢,此感應電勢由測量管上的兩個檢測電極檢出。用下列公式表示:E=KBVD式中: E-感應電勢,K-與磁場分布及軸向有關的系數(shù),B-磁感應強度,V-導電液體平均流速, D-兩電極的距離。
特點:• 傳感器采用整體焊接結(jié)構,密封性能良好。• 結(jié)構簡單,,無可動部件,幾乎無壓力損失,工作壽命長。• 傳感器無節(jié)流部件,不存在堵塞現(xiàn)象,因而適用于測量有懸浮物,固體顆粒,纖維等兩相流,另外由于清洗和滅菌消毒方便,故特別適用于食品和制藥工業(yè)。• 測量精度不受被測介質(zhì)壓力,溫度,密度(包括液固比)粘度等物理參數(shù)變化的影響。• 采用低頻二值矩形波勵磁及采樣放大技術,抗干擾能力強,零點穩(wěn)定,工作。• 儀表靈敏,輸出信號與流量成正比,量程比寬。• 耗電量小,成套儀表耗電量小于 30VA,與傳感器的口徑大小無關。• 傳感器可提供防爆型(混合隔爆型),防爆等級 mdⅡBT4。• 傳感器與 JD090型轉(zhuǎn)換器配套,可測正/反二個方向的流量。主要技術參數(shù)成套精度: 口徑Φ 10~Φ250,±0.5% ±1.0%口徑Φ 300~Φ2000,±1.0%介質(zhì)電導率:>5μS/cm(水>20μs/cm)輸出信號: 4~20mA DC0~10mA DC(按用戶需要)最大工作溫度: 口徑Φ10~Φ200 80,120,150℃三種(根據(jù)襯里材料不同)口徑Φ 250~Φ1200 <80℃最大工作壓力: 口徑Φ 10~Φ50 4.0MPa口徑Φ 65~Φ125 1.6MPa口徑Φ 150~Φ1000 1.0MPa口徑Φ 1200~Φ2000 0.6MPa
The SP4M single point load cells are now available as the successors to the successful SP4 series for maximum capacities from 1 kg up to 200 kg. The major innovation: The load cells now also offer C6 quality and therefore maximum measurement accuracy. However, a lot has been done with regard to the C3 quality models too: A broad choice of options ensures maximum flexibility.
Advantages of C6 quality:
'C6' denominates a load cell's accuracy with regard to its error limits (mpe) according to the OIML R60 international recommendation. It is the highest measurement accuracy that can currently be attained in strain-gage technology based mass-production. Load cells with C6 accuracy enable legal-for-trade scales with a permissible number of 6000 verification intervals to be produced. There are two direct advantages:
Precix series offers tested C6 quality
Many manufacturers promise load cells with C6 accuracy. With HBM you can trust in real and reliable C6 quality. This has been proven in many tests: The precix series comprising all HBM load cells in C6 quality ensures extremely precise test results. Linearity, hysteresis, dead load output return, and all other parameters required for a legal-for-trade load cell invariably have ideal values. HBM's labels live up to their promises: C6 quality on the label means C6 quality inside.
C6 quality is available for SP4M series load cells with the following maximum capacities: 7kg, 10kg, 15kg, 18kg and 36kg and, optionally, also 20kg and 30kg.
Maximum flexibility thanks to many options
Few single point load cells offer absolute measurement accuracy like this combined with so many options that enable use in numerous applications. By default, the models from this series are delivered with a 3 m long, shielded, robust 6-wire connection cable. They offer IP67 protection and have been designed for assembling multi-interval weighing machines. With models in C3 quality, the modular principle enables users to custom-assemble load cells for their special needs.
Select:
The excellent price-to-performance ratio of the models from this load cell series for universal use makes them the perfect choice.