Sensor Possibilities (LISTS)

Project to send a balloon into lower space with payload
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Rris
Posts: 66
Joined: Mon 12 Oct 12 2009 9:17 pm

Sensor Possibilities (LISTS)

Post by Rris » Fri 03 Dec 03 2010 11:50 am

Temperature sensors which go down to very low temperatures are mostly analogue output. The DS18S20 is the only digital in the list, has the most accuracy with the -55c minimum. Temperatures at altitude may go to -59c, however this sensor may read outside it's boundaries. Unfortunately, it is also the most expensive.

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Manufacturer				Part		Minimum		Maximum		Output		Min Volt	Max Volt	Accuracy	SMT			PTH		SMT CT Price	Datasheet
Maxim Integrated Products	MAX6605		-55°c		125°c		Voltage		2.70v		5.50v		0.75°c		SOT-323-5	-		$5.17 			http://datasheets.maxim-ic.com/en/ds/MAX6605.pdf
Maxim Integrated Products	DS18S20		-55°c		125°c		Digital		3.00v		5.50v		0.50°c		SOIC-8		TO-92	$5.70 			http://datasheets.maxim-ic.com/en/ds/DS18S20.pdf
Microchip Technology		MCP9700		-40°c		125°c		Voltage		2.30v		5.50v		1.00°c		SOT-323-5	TO-92	$0.38 			http://ww1.microchip.com/downloads/en/DeviceDoc/21942e.pdf
Analog Devices Inc			TMP36		-40°c		125°c		Voltage		2.70v		5.50v		1.00°c		SOT-23-5		TO-92	$1.35 			http://www.analog.com/static/imported-files/Data_Sheets/TMP35_36_37.pdf
Microchip Technology		MCP9701		-40°c		125°c		Voltage		3.10v		5.50v		1.00°c		SOT-323-5	TO-92	$0.38 			http://ww1.microchip.com/downloads/en/DeviceDoc/21942e.pdf
Microchip Technology		TC1047		-40°c		125°c		Voltage		2.50v		5.50v		0.50°c		SOT-23-3		-		$0.74 			http://ww1.microchip.com/downloads/en/DeviceDoc/21498c.pdf
Microchip Technology		TC1046		-40°c		125°c		Voltage		2.50v		5.50v		0.50°c		SOT-23-3		-		$0.70 			http://ww1.microchip.com/downloads/en/DeviceDoc/21496b.pdf

Rris
Posts: 66
Joined: Mon 12 Oct 12 2009 9:17 pm

Re: Sensor Possibilities (LISTS)

Post by Rris » Fri 03 Dec 03 2010 12:16 pm

My personal aim is 90,000 ft.
at 90,000ft... pressure is 0.26psia or 1.79kPa (17.9hPa)


From Wikipedia:

Types of pressure measurements
Pressure sensors can be classified in terms of pressure ranges they measure, temperature ranges of operation, and most importantly the type of pressure they measure. In terms of pressure type, pressure sensors can be divided into five categories:
Absolute pressure sensor
This sensor measures the pressure relative to perfect vacuum pressure (0 PSI or no pressure). Atmospheric pressure, is 101.325 kPa (14.7 PSI) at sea level with reference to vacuum.

Gauge pressure sensor
This sensor is used in different applications because it can be calibrated to measure the pressure relative to a given atmospheric pressure at a given location. A tire pressure gauge is an example of gauge pressure indication. When the tire pressure gauge reads 0 PSI, there is really 14.7 PSI (atmospheric pressure) in the tire.

Vacuum pressure sensor
This sensor is used to measure pressure less than the atmospheric pressure at a given location. This has the potential to cause some confusion as industry may refer to a vacuum sensor as one which is referenced to either atmospheric pressure (i.e. measure Negative gauge pressure) or relative to absolute vacuum.

Differential pressure sensor
This sensor measures the difference between two or more pressures introduced as inputs to the sensing unit, for example, measuring the pressure drop across an oil filter. Differential pressure is also used to measure flow or level in pressurized vessels.

Sealed pressure sensor
This sensor is the same as the gauge pressure sensor except that it is previously calibrated by manufacturers to measure pressure relative to sea level pressure.



At this point, i can't find a pressure sensor suited to our requirements.

Rris
Posts: 66
Joined: Mon 12 Oct 12 2009 9:17 pm

Re: Sensor Possibilities (LISTS)

Post by Rris » Fri 03 Dec 03 2010 1:22 pm

Humidity sensors on digikey are all Honeywell. The 5030 or 5031 (5030 with filter on it) appear to be most suitable, and cheapest which is nice.

All sensors below are capacitive type with 0-100% RH, -40 to 85c operation, 5s response time, linear voltage output.

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Manufacturer					Part		Accuracy	Min Volt	Max Volt	Filter	Price	Datasheet
Honeywell Sensing and Control	HIH-5030		3			2.7			5.5					11.23	http://sensing.honeywell.com/index.cfm/ci_id/155943/la_id/1/document/1/re_id/0
Honeywell Sensing and Control	HIH-4030		3.5			4			5.8					13.69	http://sensing.honeywell.com/index.cfm/ci_id/142958/la_id/1/document/1/re_id/0
Honeywell Sensing and Control	HIH-5031		3			2.7			5.5			X		14.11	http://sensing.honeywell.com/index.cfm/ci_id/155943/la_id/1/document/1/re_id/0
Honeywell Sensing and Control	HIH-4031		3.5			4			5.8			X		16.85	http://sensing.honeywell.com/index.cfm/ci_id/142958/la_id/1/document/1/re_id/0
Honeywell Sensing and Control	HIH-4000		3.5			4			5.8					21.33	http://sccatalog.honeywell.com/pdbdownload/images/hih-4000.series.chart.1.pdf

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