The oil quality analyzer is a portable instrument which measures the effect of contamination and electro-chemical changes that occur in lubricants. It detects and measures the dielectric constant of oil. By comparing the measurements obtained from used and unused oils of the same brand, the oil quality analyzer is able to determine the degree of change in the dielectric constant of the oil. Dielectric change is directly related to the degradation and contamination level of the oil and helps the user to optimize intervals between oil changes and to detect increased mechanical wear and loss of the oils lubricating properties. To facilitate trending the instrument is equipped with a numerical read-out. Advantages 1. Determining the degree of contaminate within 5 minutes; 2. Detecting metal particles beyond 60um; 3. Determining whether the newly purchased lubricant is qualified; 4. Determining whether the lubricant includes light oil; 5. Detecting the percentage of water content below 0. 05% within 3 minutes;