I know words like "ultra" aren't helpful, but anyway I need to use a CO2 sensor that requires "... the impedance of amplifier should be within 100—1000GΩ,Its testing current should be control below 1pA." That's "ultra" in my book!
Here's the datasheet for the sensor:
http://www.parallax.com/Store/Senso...ortField/0/Level/a/ProductID/616/Default.aspx
I believe all I need to do is convert a 30-50mV signal at that high impedance, to a "low" impedance, something I could measure with a DMM or other data acquisition scheme. Voltage amplification would be a plus.
Any alternative ideas or advice highly appreciated. The long-run goal is to make a rapid-response feedback to blood oxygenation level, as measured by exhaled CO2.
Here's a similar device:
http://www.alphasense.com/alphasense_sensors/co2_carbon_dioxide_sensors.html
Its datasheet refers to a signal conditioning box. That's what I need to do.
Here's the datasheet for the sensor:
http://www.parallax.com/Store/Senso...ortField/0/Level/a/ProductID/616/Default.aspx
I believe all I need to do is convert a 30-50mV signal at that high impedance, to a "low" impedance, something I could measure with a DMM or other data acquisition scheme. Voltage amplification would be a plus.
Any alternative ideas or advice highly appreciated. The long-run goal is to make a rapid-response feedback to blood oxygenation level, as measured by exhaled CO2.
Here's a similar device:
http://www.alphasense.com/alphasense_sensors/co2_carbon_dioxide_sensors.html
Its datasheet refers to a signal conditioning box. That's what I need to do.
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