*次坐飛機。想問空姐要一杯水。
當時出現(xiàn)了一個問題，不知道應該怎么稱呼空姐。
想了想，是不是要叫“服務員”，但是這樣顯然會暴露我*次坐飛機的本質，*沒有逼格。“服務員”這么鬼？是飯館么？顯然不行。
于是，在我緊張飛速的思緒轉動之后，冒出這么一句——“師傅，麻煩您給我倒一杯果汁！”

Dwyer 677B系列 差壓變送器

品牌：dwyer  
產品描述：
NEMA 4 外殼，整體安裝
Series 677B Differential Pressure Transmitters Are Designed To Measure Pressures As Low As 0.1 In W.C. With ±0.4% Accuracy. Use Series 677B For Building Energy Management Systems, Environmental Pollution Control, Oven Pressurization, Lab And Fume Hood Control, HVAC And VAV Applications. The Transmitter Features 15 Psid Overpressure, Reverse Polarity Protection And EMI/RFI Protection. Internal Regulation Permits Use With Unregulated DC Power Supplies. The NEMA 4 Housing Allows For Versatile Mounting Locations And Integral Mounting Tabs Simplify Installation.
Dwyer 677B系列 差壓變送器
Service: Air And Non-Conductive, Non-Corrosive Gases.
Wetted Materials: 302 SS, Glass, Nickel, Silicone Rubber And Brass.
Accuracy: ±0.4% FS* At Room Temperature. *RSS Includes Non-Linearity, Hysteresis And Non-Repeatability.
Stability: ±1% FS/Yr.
Temperature Limits: 
Operating And Compensated: 0 To 185°F (-18 To 85°C);
Storage: -65 To 220°F (-54 To 105°C).
Pressure Limit: 15 Psi (100 KPa).
Thermal Effects: (Includes Zero And Span) <0.028% FS/°F, 0 To 185°F (-18 To 85°C).
Power Requirements: 16 To 32 VDC.
Output: 4 To 20 MA DC, 2-Wire.
Zero And Span Adjustments: Internally Accessible Potentiometers, Noninteractive.
Response Time: Approximay 10 Ms.
Max. Loop Resistance: DC: 0 To 800 Ohms.
Process Connection: 3/16" OD Barbed Brass Pressure Fitting.
Enclosure Rating: NEMA 4 (IP65).
Weight: 11.5 Oz (330 G).
Agency Approval: CE.
Dwyer 677B系列 差壓變送器
附件:
NISTCAL-PT1 - NIST Traceable Calibration Certificate For Pressure Transmitters.
A-302F-A - 303SS Static Pressure Tip With Mounting Flange, 4" Hook Style. For 3/16" ID Rubber Or Plastic Tubing, Includes Mounting Screws.
A-489 - 4" 303 SS Straight Static Pressure Tip With Flange.