Dear Salah,

There are two available methods: Weighing the collected salivary volume & the use of hypodermic graduated syringes:

Weighing the collected salivary volume is not a practical method in public health services. A study entitled "Use of Graduated Syringes for Measuring Salivary Flow Rate: A Pilot Study " evaluated the use of hypodermic graduated syringes as a simpler alternative method to measure the salivary flow rate. Saliva samples were obtained from 50 individuals (31 females and 19 males) aged 8 to 32 years (mean age: 12.4 years), recruited at the outpatient dental clinics of two public health centers. After collection, the saliva was weighed in a graduated scale and the results compared with the volume obtained through its measurement, in mL, in graduated hypodermic syringes. There was a positive and significant relationship between the two methods of measuring salivary flow rates as demonstrated by the Pearson’s correlation coefficient (r = 0.996, with p