Effective detection of OCR
The commonly used method for detecting the oil content in refrigerants is the sampling and weighing method. However, this method is very time consuming, a certain amount of oil and refrigerant is taken out of the system, and the results obtained do not reflect the real-time phenomenon. Therefore, many people try to develop other methods to replace this traditional detection method, in order to clearly quantify the exact composition of the mixture. Over the years, a large number of technical methods have been developed to successfully achieve real-time detection of the concentration of the fluid in the working state in the cooling system. These methods include a wide range of spectroscopic techniques; from liquid density detection to sound velocity methods, optical absorption methods, non-conductivity constant methods, and finally refractive index measurements. However, not all of these techniques are completely satisfactory.
and to convince people that the results are accurate, reliable and valuable. Therefore, FISO Technologies has developed a system consisting of a fiber-optic refractive index sensor (FRI) and a signal conditioner to accurately measure OCR. This OCR inspection solution meets the inspection requirements of engineers working in the field of refrigeration.

First, the resolution of the oil concentration ratio is higher than 0.04%. Recently, a series of experiments jointly conducted by Danfoss Commercial Compressor Company and a third-party laboratory showed that when FISO's fiber-optic refractive index sensor FRI is used with FTI-10 single-channel signal conditioner to detect POE oil content in R 410a refrigerant, the resolution can reach 0.036 percent.

Secondly, the sensor is very easy to install in the cooling system. The FRI-NP sensor is mounted on a stainless steel rod (1/8 ") which can be supplied with a Swagelock NPT connection. Some customers prefer to use a connector of their choice (such as CONAX's or another company's), which is usually easy to fix on the SS sensor stick. This installation method has little interference with the system, and the result also reflects the actual situation. If the customer needs, can also provide a diameter of less than 0.032 inches (0.8mm) bare plate refractive index sensor (FRI-BA), this bare plate sensor can be installed into a thinner tube, used to FRI-NP the sensor size is inconvenient to install the place. Both of these sensors are directly effective for continuous detection.