Editing BioBoard/Documentation/Optical loss
Jump to navigation
Jump to search
The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then publish the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 95: | Line 95: | ||
=Calibrating= | =Calibrating= | ||
Calibrating measuring equipment is an important part of any scientific pursuit, because the accuracy of your calibration determines the reliability of your data. However | Calibrating measuring equipment is an important part of any scientific pursuit, because the accuracy of your calibration determines the reliability of your data. However, determining absolute accuracy may be somewhat difficult, so you might want consider whether you actually need absolute values; in a lot of cases, you are likely to be less interested in the absolute biomass than in the relative change in biomass over time. | ||
To get an absolute measure of biomass in a live microbial culture, you can use several different techniques: | To get an absolute measure of biomass in a live microbial culture, you can use several different techniques: | ||
Line 118: | Line 118: | ||
If you have problems covering the whole spectrum, the other two things you can adjust relatively easily are the distance between the LED and the phototransistor, and the resistance on the circuit. A low resistance potentiometer instead of the 100Ω resistor on the emitter lead would allow you to adjust the sensitivity of the phototransistor directly, and provide a way of tuning it without having to disassemble and rebuild it. You can also decrease the light intensity of the LED by increasing the value of the resistor; 470Ω seems to be a good mid-level. | If you have problems covering the whole spectrum, the other two things you can adjust relatively easily are the distance between the LED and the phototransistor, and the resistance on the circuit. A low resistance potentiometer instead of the 100Ω resistor on the emitter lead would allow you to adjust the sensitivity of the phototransistor directly, and provide a way of tuning it without having to disassemble and rebuild it. You can also decrease the light intensity of the LED by increasing the value of the resistor; 470Ω seems to be a good mid-level. | ||
=Geeking out= | =Geeking out= |