Fórum | MyPower.CZ | Obnovitelné zdroje energie - energetická soběstačnost | Poslední návštěva: sob bře 06, 2021 1:09 pm
pán píše:"Dobré pro spínání ventilace s přesností +-500ppm CO2, pokud chcete měřit jednotky ppm budete si muset připlatit za NDIR... Čidlo se totiž chová pokaždé jinak, stupnice se posouvá nahoru a dolu, takže je nemožné zkalibrování. Koupil jsem tři a dělají to všechny. Porovnáváno s měřákem Wohler CDL 210 cca 10 dní. Vše zapájeno napevno (nepájivé pole nepoužitelné), napětí stabilizované, teplota 20stup., vlhkost 50procent.... Hodně štěstí"
Determine the Voltage at 40000 ppm (exhalation concentration)
Next obtain a plastic bag of length about 30 cm and width 22 cm. Snip one corner of the bag to leave a tiny hole opposite to the open end. This is the ‘exhaust vent’. Inflate the bag as best as possible and then, without switching the unit off or disturbing the wiring, carefully place the complete unit in the bag. Make sure the plastic is kept well clear of the sensor. Inserting the device in an open top plastic box or rigid container may help. Connecting wires to the power supplies will be through the open end of the bag. Close the open end as best as possible and, very gently, exhale into the bag through the open end (rather like inflating a balloon). Pinch the exhaust vent completely, while taking fresh breath, to prevent ambient air entering the bag. The exhaust hole should also be semi restricted when exhaling air into the bag to allow the bag to inflate. Within a few minutes the bag will be virtually entirely filled with exhaled air at 40000 ppm. The downside is that the relative humidity will be 100% but this does not seem to be a problem other than making it difficult to read the display. When the display reading remains constant for approximately 30 seconds steady state has been reached (at about 2 - 2.5 volts below the 400 ppm voltage). Ideally keep exhaling for another 30 seconds to make sure and then note the voltage and carefully remove the bag. The whole process takes about 5 minutes and, again, the more effort put into it, the better will be the accuracy of the sensor. The voltage value at 40000 ppm is defined as v40000ppm.
Calibration is now complete. This method can enable good agreement with other sensors as shown in the calibration figure which illustrates virtually perfect correlation with a Non-Dispersive Infra Red (NDIR) sensor.
Dreambox píše:http://www.co2meter.com/products/s8-miniature-co2-sensor
$85.00
Zpět na Automatizace, měření, statistiky
Uživatelé procházející toto fórum: CC [Bot] a 0 návštevníků