1046 User Guide - Revision history

Mparadis at 14:28, 9 May 2018

2018-05-09T14:28:29Z

← Older revision		Revision as of 14:28, 9 May 2018
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			__NOINDEX__
	[[Category:UserGuide]]		[[Category:UserGuide]]
	{{UserguideTOC\|1046.jpg\|1046}}		{{UserguideTOC\|1046.jpg\|1046}}

Mparadis: /* Product History */

2016-04-20T14:57:03Z

Product History

← Older revision		Revision as of 14:57, 20 April 2016
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	{{UGrow\|May 2011\|0\|100\|Product Release}}		{{UGrow\|May 2011\|0\|100\|Product Release}}
	{{UGrow\|May 2011\|0\|101\|getLabelString fixed for labels longer than 7 characters}}		{{UGrow\|May 2011\|0\|101\|getLabelString fixed for labels longer than 7 characters}}
			{{UGrow\|February 2014\|0\|102\|Various fixes: usb stack, gain switching, bad values after enable}}

Mparadis: /* Measuring Resistive Thermal Devices (RTD) */

2013-08-08T21:05:53Z

Measuring Resistive Thermal Devices (RTD)

@@ Line 126: / Line 126: @@
 Using a slower sampling rate will reduce the noise in the measurements dramatically.  The noise figures are specific to individual applications and sensors.  The lowest noise level achievable is 5nV/V RMS.
-===Measuring Resistive Thermal Devices (RTD)===
+{{RTDinfo}}
 ==API==

Mparadis: /* Connecting your Strain Gauge/Load Cell */

2013-08-08T21:04:48Z

Connecting your Strain Gauge/Load Cell

← Older revision		Revision as of 21:04, 8 August 2013
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	===Connecting your Strain Gauge/Load Cell===		===Connecting your Strain Gauge/Load Cell===

			Load cells are pressure sensors that can be used with the 1046 - PhidgetBridge.

			For more information, see our [[Load Cell Primer]].

	If no documentation is available for your strain gauge, it’s possible to use a multimeter to determine how to connect it, provided there are no electronics in the sensor. First, measure resistance between the 4 wires. There are 6 combinations - two combinations will have a resistance 20-40% higher than the other four. Choose one of these high-resistance combinations, and wire it into 5V and G on the PhidgetBridge. Connect the other two wires into +/-. Apply a load - if the mV/V responds in the opposite way to your expectations, flip the +/- wires.		If no documentation is available for your strain gauge, it’s possible to use a multimeter to determine how to connect it, provided there are no electronics in the sensor. First, measure resistance between the 4 wires. There are 6 combinations - two combinations will have a resistance 20-40% higher than the other four. Choose one of these high-resistance combinations, and wire it into 5V and G on the PhidgetBridge. Connect the other two wires into +/-. Apply a load - if the mV/V responds in the opposite way to your expectations, flip the +/- wires.

Mparadis: /* Load Cells */

2013-08-08T21:04:24Z

Load Cells

← Older revision		Revision as of 21:04, 8 August 2013
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	* Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.		* Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.
	* By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.		* By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.

	~~====Load Cells====~~

	~~Load cells are pressure sensors that can be used with the 1046 - PhidgetBridge.~~

	~~For more information, see our [[Load Cell Primer]].~~

	==API==		==API==

Mparadis: /* Product History */

2012-11-27T17:19:44Z

Product History

← Older revision		Revision as of 17:19, 27 November 2012
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	{{UGhist}}		{{UGhist}}
	{{UGrow\|May 2011\|0\|100\|Product Release}}		{{UGrow\|May 2011\|0\|100\|Product Release}}
			{{UGrow\|May 2011\|0\|101\|getLabelString fixed for labels longer than 7 characters}}

Mparadis: /* Technical Details */

2012-08-21T18:44:24Z

Technical Details

← Older revision		Revision as of 18:44, 21 August 2012
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	* Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.		* Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.
	* By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.		* By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.

			====Load Cells====

			Load cells are pressure sensors that can be used with the 1046 - PhidgetBridge.

			For more information, see our [[Load Cell Primer]].

	==API==		==API==

Mparadis: /* Technical Details */

2012-08-16T19:43:10Z

Technical Details

← Older revision		Revision as of 19:43, 16 August 2012
Line 121:		Line 121:

	Using a slower sampling rate will reduce the noise in the measurements dramatically. The noise figures are specific to individual applications and sensors. The lowest noise level achievable is 5nV/V RMS.		Using a slower sampling rate will reduce the noise in the measurements dramatically. The noise figures are specific to individual applications and sensors. The lowest noise level achievable is 5nV/V RMS.

			===Measuring Resistive Thermal Devices (RTD)===

			====Using a Wheatstone Bridge====

			[[File:1046 0 WheatstoneRTD.jpg\|thumb\|400px\|link=\|This diagram shows how to connect the RTD to a Wheatstone bridge, and then to a PhidgetBridge 4-Input.]]
			A Wheatstone bridge is the classic method of measuring unknown resistances, and requires three resistors of known values. It uses the current in each leg of the bridge to create a voltage differential between both voltage dividers. Using the voltage differential and the three known resistors, the resistance of the fourth resistor can be determined.

			To determine the resistance of the RTD, the following formula can be used:


			:<math>
			R_{RTD} = \frac{R_3 \times [R_2 + V_B \times (R_1 + R_2)]}{R_1 - (R_1 + R_2) \times V_B }
			</math>


			Where <math>V_B</math> is the Bridge Value given by the PhidgetBridge (in mV/V) , and <math>R_1</math>, <math>R_2</math> and <math>R_3</math> are the resistances of the known resistors.

			<br clear=all>

			====Using a Voltage Divider====
			The alternate method requires only two resistors. This reduces the amount of error that can be introduced into the system due to resistor tolerances. A voltage is applied to the two resistors and the RTD in series. The voltage drop across the RTD is measured. Using the voltage drop and the values of the two resistors, the resistance of the RTD can be determined.

			[[File:1046 0 Diagram.jpg\|thumb\|400px\|link=\|This diagram illustrates how to connect the RTD to the PhidgetBridge with a voltage divider cirtuit.]]

			To determine the resistance of the RTD, the following formula can be used:


			:<math>
			R_{RTD} = (R_1 + R_2) \times \frac{V_B}{1 - V_B}
			</math>


			Where <math>V_B</math> is the Bridge Value given by the PhidgetBridge (in mV/V) , and <math>R_1</math> and <math>R_2</math> are the resistances of the known resistors.
			<br clear=all>

			====Getting Higher Accuracy====

			In order to get the highest accuracy from the RTD, consider the following:

			* Use resistors with a high degree of tolerance. There will be less variability in the manufacturing of 0.1% resistors when compared to 1% resistors.
			* Measure the known resistors with an ohmmeter. By obtaining the most accurate measurements for the known resistances, the formula will result in a more accurate measurement of the RTD.
			* Use a moving average when obtaining the Bridge Value to reduce the amount of noise in the measured signal.
			* Estimate or Measure the resistance of the +5V and GND wires between the RTD and the 1046 PhidgetBridge. Add this resistance to the two resistors.
			* Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.
			* By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.

	==API==		==API==

Burley at 15:16, 10 August 2012

2012-08-10T15:16:59Z

← Older revision		Revision as of 15:16, 10 August 2012
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	[[Category:UserGuide]]		[[Category:UserGuide]]
			{{UserguideTOC\|1046.jpg\|1046}}
	==Getting Started==		==Getting Started==

Mparadis at 15:41, 26 July 2012

2012-07-26T15:41:14Z

← Older revision		Revision as of 15:41, 26 July 2012
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			[[Category:UserGuide]]

	==Getting Started==		==Getting Started==

← Older revision		Revision as of 14:57, 20 April 2016
Line 186:		Line 186:
	{{UGrow\|May 2011\|0\|100\|Product Release}}		{{UGrow\|May 2011\|0\|100\|Product Release}}
	{{UGrow\|May 2011\|0\|101\|getLabelString fixed for labels longer than 7 characters}}		{{UGrow\|May 2011\|0\|101\|getLabelString fixed for labels longer than 7 characters}}
			{{UGrow\|February 2014\|0\|102\|Various fixes: usb stack, gain switching, bad values after enable}}