The present invention is directed to a method of lubricating a conveyor system comprising i) diluting a conveyor lubricant concentrate with water to obtain an aqueous conveyor lubricant with the concentration c, ii) irradiating an aqueous conveyor lubricant with light, iii) determining the concentration c of the aqueous conveyor lubricant by measuring the absorption of the light by the aqueous conveyor lubricant with an absorption detector and iv) applying the aqueous conveyor lubricant to the conveyor system. The present invention further relates to a conveyor lubrication system including a measuring device with a light source and with an absorption detector for measuring the absorption of light by an aqueous conveyor lubricant within a conveyor lubrication system.