View source for 1139 User Guide

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<metadesc>The Phidget Differential Air Pressure Sensor plugs into an Analog Input or VINT Hub port and measures pressure from 0 kPa to 100 kPa.</metadesc>
[[Category:UserGuide]]
==Getting Started==
{{UgSensorIntro|1139|Differential Air Pressure Sensor 100 kPa|Voltage Ratio Input port}}


Next, you will need to connect the pieces:
[[Image:1139_0_Connecting_The_Hardware.jpg|400px|right|link=]]
# Connect the 1139 to the HUB0000 with the Phidget cable.
# Connect the HUB0000 to your computer with the USB cable.

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{{UGIntroDone|1139}}

==Using the 1139==
{{UGcontrolpanelSensor|1139|HUB0000}}

{{UGSensorVoltageRatioInput|1139|pressure (kPa)}}

==Technical Details==
===General===
The 1139 uses bipolar processing to provide an accurate, high level analog input signal that is proportional to the applied pressure. When the sensor is plugged in, the sensor voltage should default to about 0.2V, which corresponds to 0 kPa between the two ports.

===Ports===
The sensor comes with a positive top port and a negative bottom port. These ports have a diameter of 2.79mm to 3.30 mm (nominal 3mm). 

Take caution when connecting the pressure ports- this sensor only measures a positive pressure differential, and you could damage the sensor if you connect it in reverse. Ensure that the upper port is always at an equal or higher pressure than the lower port. 

[[File:1138_0_Ports.jpg|300px|right|link=]]

For hosing, we recommend using polyurethane tubing.  We have had good results with 2.4mm ID tubing from [http://www.emicorp.com/ EMI]. In imperial measurement, 3/32” ID tubing is equivalent. This is available through laboratory supply stores such as [https://www.coleparmer.com/ Cole Parmer].

===Formulas===
{{UGSensorFormula|pressure (kPa)}} The Formula to translate voltage ratio into Pressure is:


:<math>
\text{Pressure (kPa)}= \frac{\text{VoltageRatio} \times 1000}{9}  - 4.444
</math>



:<math>
\text{Pressure (psi)} = (\text{VoltageRatio} \times 16.11)  - 0.6444
</math>

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{{UGasens}}

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