Introduction to PetroSense
The increasing concern about hydrocarbon contamination of process water and produced water has created an increasing need for in-situ, real time, and accurate low cost instrumentation that can provide rapid detection and easily usable in the field.
PetroSense® sensors [1,2] represent "best in breed" technology for the detection of total petroleum hydrocarbons (TPH). PetroSense sensors are incorporated in both a portable, field screening instrument the PHA-100 and a continuous monitoring system the CMS-4000. These sensors utilize fiber optic systems and are designed for in-situ, real time measurements of TPH and other related pollutants.
PetroSense sensors operate in air (vapor), water and soil.
PetroSense sensors are non-specific detectors for TPH, semi-volatile hydrocarbons (e.g., diesel fuel, heating fuels, etc.), richloroethylene/perchloroethylene and many other related compounds. The detection capability of these sensors is unaffected by high humidity, or by naturally occurring methane. PetroSense sensors have been used in a variety of applications:
- In-situ vapor measurements in wells
- In-situ water measurements in wells
- Cooling Tower monitoring
- Water measurements in bailed samples from wells
- Surface water measurements
- Tracking of a hydrocarbon leak in progress (plume migration)
- In-situ monitor for vapor extraction systems
- Leak detection for above ground and underground storage tanks
- Leak detection for pipelines
- Storm water runoff monitoring
- Sample screening for laboratory analyses
- Site assessment
- Groundwater remediation
Although these sensors are non-specific, there is a relative response characteristic for the different compounds that are detected. The PetroSense sensors have a very strong response for aromatic and other large hydrocarbon compounds. This makes these sensors very useful for the detection of BTEX (benzene, toluene, ethyl benzene and xylenes), which is used as a tracer for TPH leaks/contamination. The characteristic relative response factors (RRF's) can be determined for specific sites. The sensors can be calibrated for specific compounds expected at a given site, or the non-specific readings can be converted to the concentrations of these specific compounds by use of the appropriate RRF's.
 "Fiber Optic Chemical Sensor (FOCS®) Technology for the Detection of Hydrocarbons in Air and Dissolved in Water: PetroSense® Portable Hydrocarbon Analyzer (PHA 100) and the PetroSense® CMS 5000" D. P. Saini, R. Himka, S. Klainer, M. Arrasate, R. Leclerc, Field Screening Symposium.
Las Vegas, Nevada, 22-24 February 1995.
 PetroSense® CMS 5000, A Fiber Optic Sensor Sensing System for the Continuous Monitoring of Hydrocarbons" D. P. Saini, R. Leclerc, S.M. Klainer, R.L. Himka, H. Arman, D.K. Dandge, O. W. Wolfbeis, B. Kovacs. 2nd European Conference on Optical Chemical Sensors and Biosensors.
Firenze, Italy, April 19- 21
Word From An Independent Study:
Fiber Optical Sensor (FOCSTM) System – used to directly and quickly monitor concentration of total petroleum hydrocarbons in the air, at the air/water interface, and dissolved in water. FCI's hydrocarbon sensor is designed to monitor the concentration of dissolved BTEX in water, liquid product at the air/water interface , and BTEX in vapor.
PetroSense sensors are very sensitive to BTEX and its individual components dissolved in water. The Sensors are capable of detecting low concentrations of BTEX with a high degree of accuracy. FCI’s sensors match readings taken via the gas chromatograph with at least a 98% correlation." Based on a comparison with EPA Method 8020.
The PetroSense sensors begin to respond immediately to the presence of BTEX hydrocarbons dissolved in water. They provide quantitative results in ppm of the compound used to calibrate the system. When measuring blind samples of p-xylene the probes correlate with the GC at the 99% level. The blind samples run with benzene (RRF of 6.233) showed a quantitative correlationof 97% with the GC and UV. Toluene (RRF of 2.857) gave similar results with a correlation of 98%. Ethyl benzene (RRF of 1.034) had a correlation of 98%. And when run with a 1:1:1:1 mixture of BTEX the average RRF is 1.730 and the correlation was 98%.
And Quick In the presence of product, the sensors achieve a 95% detection level in approximately 5 minutes. When the sensors are removed from contaminated water containing a product and placed in chemical-free water, the fall back time to a baseline reading occurs in approximately 2 minutes.