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PHOTONIS USA Resistive Glass Capillary Inlet Tubes. Background Resistive Glass Products are geometric glass structures with resistive properties that can be used to create uniform electric fields in order to guide or direct charged particles
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Background • Resistive Glass Products are geometric glass structures with resistive properties that can be used to create uniform electric fields in order to guide or direct charged particles • They are fabricated from proprietary lead silicate glasses and can have thin film metallization contact points
Capillary Inlet Tube Illustration Resistive Glass Electroded end (beveled) Electroded end (beveled) Conductivity break on outside of tube
Capillary Inlet Tubes • Key application for RGPs • Sample injection in mass spectrometers • Voltage applied across resistive glass tubes creates an electric field that • Preferentially attracts ions into inlet tube and rejects ambient species • Forces more ions into the mass spec E Sample Chamber (ambient pressure) Mass spec (vacuum) + +
Capillary Inlet Tubes • Otherwise collisions with other ions and tube walls may result in ions traveling back • Therefore, compared to conventional quartz tubes resistive glass inlets provide more efficient sample transfer without analysis of unwanted background E Sample Chamber (ambient pressure) Mass spec (vacuum) + +
A leading mass spec manufacturer currently uses our inlet tubes in their LC/MS Q-TOF • Planning to implement resistive glass inlet tubes across entire line of mass spectrometers • PHOTONIS USA manufacturing capability: • +/- 0.025 mm tolerance on OD and ID • Custom end designs to accommodate specific cap configurations • Custom electroding and sandblasting patterns
Properties of PHOTONIS USA Resistive Glasses • Resistance Uniformity: • 1.5 to 2.5% variation in resistance of flat plates of various sizes • Less than 1% variation in resistance of tubes of 30mm length. • Kelvin probe data indicates uniform resistance results in uniform electric fields and the glass acts as a good conductor with no surface charging. • Resistance Stability : • Tubes are very stable in vacuum and nitrogen • Moderate increase in resistance observed in room air over time • The rate of increase slows with time but the resistance has been seen to continue to increase for over 6 months • Resistance also decreases at elevated temperatures