Pyxis HM-500 Series Oil-in-Water Sensors

The Pyxis HM-500 series (HM-500, HM-510, HM-520) are inline sensors that measure the concentration of oil in water by UV fluorescence, read as ppm Marine-Offshore Oil. They use a 365 nm LED and 410/470 nm wavelengths and cover three ranges (0-10, 0-100 and 0-1,000 ppm) in two housing materials, CPVC or 304 stainless steel, for six models in total. Mikron Proses (Üsküdar, Istanbul) provides application consulting on choosing the range and housing for your process water.

Oil in water · Leak detection → Send us your requirement

For the measurement background, see the guide on oil-in-water measurement.

Measuring principle: UV fluorescence with color and turbidity compensation

The sensor uses a UV fluorescence method with a 365 nm LED and 410/470 nm wavelengths to measure oil concentration as Marine-Offshore Oil. The distinguishing feature of the HM-500 series is extra photo-electric components that monitor the color and turbidity of the sample water at the same time and compensate for them automatically; the manufacturer states that this compensation applies up to 150 NTU turbidity and 10 ppm iron. The short fluidic channel is easier to clean than the long, narrow flow cells of traditional fluorometers.

Three ranges, two housing materials

HM-500/HM-500SS cover 0-10 ppm (limit of detection 0.1 ppm), HM-520/HM-520SS cover 0-100 ppm (LOD 0.5 ppm) and HM-510/HM-510SS cover 0-1,000 ppm (LOD 0.5 ppm). Reproducibility is 0.1 ppm or ≤3% in all models. CPVC models come with an ST-001 3/4-inch FNPT inline tee and work up to 7 bar; 304 stainless steel (SS) models work up to 21 bar and are intended for harsh applications. CPVC models can also be used in submerged installations with the MA-102S submersion adapter kit.

Outputs and wireless diagnostics

All models provide a 4-20 mA analog and an RS-485 Modbus RTU digital output at the same time and run on 24 (±2) VDC at 65 mA. With an MA-WB Bluetooth adapter or a PowerPACK series auxiliary box, the uPyxis app can run a wireless sensor cleanliness diagnosis (result in 5 seconds) followed by a 2-point calibration, so calibration is carried out on the sensor itself instead of through the receiving controller. Protection is IP67; operating temperature is 4-40 °C.

Calibration standard: OIW-500

Pyxis offers a 500 ppm synthetic OIW-500 secondary oil-in-water standard (as Marine-Offshore Oil, 6-month shelf life) as a more stable alternative to preparing a real oil-in-water sample for calibration. For values below the stated range, the standard can be diluted with deionized water.

Send us your requirement and we will select the range (HM-500/510/520) and housing material (CPVC or SS) together, based on your process water pressure and contamination level.