wysiwyg_imageupload:388: Mr. sikander you asked me in that image what is that arrow mark indicating on the resistance connected to the the +VE of opamp?
wysiwyg_imageupload:389: this is variable resistance denoted as RV and below written is its value
you might be calling it as trimpot, Kpot or a preset…
go for the link(below) select component tab see the description for preset.
http://www.engineersgarage.com/electronic-circuit/infrared-ir-sensor
just let me know your project updates……