CPI graphite tubes are produced from one of the highest grades of spectrally pure graphite available today.  Prior to use, the base material is tested for purity, constant density and electrical resistivity.  This critical screening ensures that our tubes are free from trace metal contamination and provide maximum, consistent life in your instrument.

Quality raw material is only the beginning of a superior graphite tube:  reproducibility, sensitivity and tube life depend on consistent, strict tolerances in milling and coating of the tube.  All equipment used in our milling processes is calibrated to hold extremely tight tolerances as low as 1/ 10,000 of an inch.  Once milling is complete, tubes meeting our tight quality control are then accepted for coating.  CVD furnaces which apply the pyrolytic coating are calibrated to apply a precise, even coating of pyrolytic graphite over the entire tube.  Years of research have proven that a precise coating thickness is required to maintain an optimal balance between reproducibility, sensitivity and life.  Upon testing each coated tube for mass, resistivity, and stable alignment of the platform, only tubes meeting our strict standards are reserved for final lot testing in a GFAA spectrometer.  These extensive QC and final test procedures ensure that you receive tubes you can count on for high sensitivity, reproducibility and long life.

CPI tubes are priced lower than the OEM and other suppliers and offer the same or better performance.  When compared with less expensive, lesser quality tubes, CPI tubes offer more value when inconsistent tube life, lower sensitivity, technician labor, and  instrumentation downtime are considered.  Because CPI tubes are designed to perform in accordance with OEM specifications, it is not necessary to reset your temperature programs, eliminating the need for time consuming optimization procedures.

Each tube was tested using Cr, and a combination of lifetime and absorption signal was observed.  The element Cr was chosen because of its demanding temperature profile (2,650 degrees C).  A lab fortified blank was used to eliminate bias.  Actual number of firings may be lower given a “real world” sample matrix.

The less expensive aftermarket tubes did not meet CPI specifications for life, sensitivity or absorption signal. These parts, manufactured in China, exhibit greater variances in performance and life. CPI tubes demonstrated excellent performance of 550 firings.