FAQ

Question	Answer
How does the measurement method work?	Measurement of the change in rotational frequency of a magnetically levitated ball located in a vacuum .
What is the size of the sensor/ball/sphere and what material is it made of?	Stainless steel 1.4034, 4.5mm, polished, hardened ball bearing ball .
Why does the system not age?	Magnetically levitated, non-contact, no filaments or hot components, no mechanical stress, hardened ball bearing ball .
Is the sensor system high-purity?	PH Instruments offers high-vacuum cleaned sensors; 3-stage cleaning (salts, metals, hydrocarbons, water vapor) (Competitors: No) .
Why sensors from PHI?	Manufacturer specifications, 100% sensor selection, 100% compatibility with the measurement method, measurement method and sensor from a single source .
Why sensor tubes from PHI?	Material selection optimized for SRG technology, diverse application-specific flanges, optionally electropolished, single piece .
What happens in the event of a power failure?	The ball loses magnetic levitation and rotates in the measuring tube . For the VIM-2, the battery takes over the power supply . Upon restart, the zero point must be reset .
Why does the method not influence the process?	No electronics in the vacuum, no filaments, no ion current, no sputtering, gettering, or outgassing in the process; purely magneto-mechanical measurement .
What is the measuring range of the method?	Specified range from 10 mbar to 5 x 10^-7 mbar (starts at 1000 mbar, but is unspecified there) .
How high is the absolute accuracy?	Absolute accuracy is +/- 1% of the reading for calibrated sensors and +/- 6% for uncalibrated, selected sensors .
Do the devices work at atmospheric pressure?	Yes, the devices function, but there are more suitable devices for applications at atmospheric pressure .
Can I bake out the systems?	Yes, the sensor systems can be baked out; pure metal construction with no electronics in the measuring tube (maximum 450 degrees Celsius) .
How complex is the mechanical installation?	Either standardized flanges are required, or the measuring tubes are welded directly to the process chamber.
How is the zero point set?	Either via the graphical user interface (GUI), the readout unit, or the button on the SRG Transducer electronics; requires an intelligent algorithm and stable pressure conditions < 2 x 10^-7 mbar.
When does the zero point change?	When the power supply is interrupted, the sensor head is removed from the tube, or communication between the head and electronics is lost.
How expensive is the system?	List price for a single Transducer is between €10,000 and €15,000; the VIM-2 system is €20,000.
Why does your measurement method not corrode?	The ball is polished (no surface for molecules to attack), made of stainless steel, operates at room temperature, and has no electrical feedthroughs .
Why is the measurement method less sensitive to coatings?	Only the ball diameter matters, not electrical properties (anode/cathode); micrometer-range coatings are irrelevant for a 4.5 mm diameter .
What materials are used in the sensor system?	Stainless steel 1.4034 and stainless steel 1.4404
How do I install the sensor tube in my application (vacuum-tight)?	Via various flanges (CF, KF) or by welding
What standard connection technologies does PHI offer?	USB Type C and High Density 15-pin
What materials can the sensor tube be made of?	Glass or stainless steel.
Does the process still work after decades?	Yes, the method remains functional even after decades .
What is the average lifespan of the sensor and evaluation unit?	10 years+; designed for tool lifetime .
What mounting position is required for the sensor tube?	Ideally horizontal (+/- 2 degrees, maximum +/- 5 degrees) to prevent tilting and ensure ideal rotation .
Is there heat generation in the sensor head?	If operated at pressures above 100 mbar, yes; a thermal sensor is installed and the device shuts down automatically at 70 degrees Celsius .
What is the Pirouette Effect?	It describes the effect of mass distribution of a rotating body on its frequency; in SRGs, the ball contracts when cooling, which can distort values .
What is the cost of the sensor alone?	Between €400 and €2,200 depending on the calibration standard and type .
Can I build sensor systems myself?	No; specifications, material properties, dimensions, and construction must match exactly .
How often does the ball re-accelerate?	Pressure-dependent; between every few seconds (at 1 mbar) and every few days (at 10^-7 mbar) .
Can I use any ball bearing ball?	No; in the best case, only 80% are suitable for selection and only 10% for high-end calibrations .
Can I measure any existing ball/sensor/sphere on the market?	Yes .
How well is the tube protected from mechanical damage?	A screwable mechanical protection tube (Heavy Duty Protection Tube) is included in the delivery .
Does the sensor work with competitor products (e.g. MKS)?	Yes.
Do I need tools to install the readout unit?	No, the readout unit is simply plugged on .
Can I replace cold cathodes?	Yes, we also offer Plug & Play solutions .
Can I replace hot cathodes?	Yes, we also offer Plug & Play solutions .
Do I have to send in the complete system for recalibration?	No, only the sensor system .
Can I clean the sensor tube/sensor myself?	Yes, it can be cleaned by the user.
Country of origin?	Austria; European suppliers.
Sustainability?	Made only of stainless steel; long service life with no waste; avoids adhesives and plastics; recalibratable and repairable .
Failure rates?	No known electrical or mechanical failures since the company was founded in 2019 .
How long is the product warranty?	1-year warranty (extendable at any time depending on the application) .
Are you ISO certified?	In progress; however, we adhere internally to ISO regulations .
Which standards are used for factory calibration?	DAkkS (accredited lab), CAL (factory calibrated based on ISO 3567/24477 with certificate), SEL (selected), and PTB (highest national standard) .
What advantages does PHI SRG offer compared to MKS SRG?	Twice as strong magnetic bearing (less sensitive to vibration/tilt), no moving parts, higher durability, Plug & Play, GUI, easier operation, and mobility (battery-powered) .
Are there competing methods?	Not in the ideal range of 10^-4 to 10^-7 mbar .
What cost advantage does the process offer?	No spare parts, no replacement of drifting filaments; unlimited lifespan (some systems in use for 30 years) .
Which components do I need to calibrate?	The ball/sensor/sphere depending on the application; some applications (e.g. Cryo) require no calibration due to high intrinsic accuracy .
Can I change the sensor myself?	Yes, the ball can be replaced by the user (for VIM-2 and Calitorr), though replacement by PH Instruments is recommended .
How many sensors can I read with one device?	Unlimited number .
Does an SRG drift?	Extremely low drift (< 1.5% per year); proven as a transfer standard by NIST, PTB, AIST, etc .
Is the sensor replaceable?	On all flanges except for weld-on studs (fixed welded retaining clip for maximum safety).
Why should the sensor be replaceable?	For recalibration, cleaning, and ISO purposes .
Can I swap the sensor myself?	Principally yes—SEL types can be done by the user; CAL/DAkkS is recommended as a service by PH Instruments.
Is absolute accuracy relevant for Chamber-to-Chamber matching?	Yes, extremely relevant (except in Cryo applications) .
How often must the zero point be adjusted?	Cryo never; Semicon depends on application (principally never in standard operation) .
Can I use the measurement method in tight spaces?	Yes, the Transducer Extend version can be used in tight spaces or removed from the process via a T-piece . A distance from Ion Gauges should be maintained to avoid contamination .
Is absolute accuracy relevant in the process?	Yes; absolute accuracy is a priority for calibration, though long-term stability (reproducibility) is even more relevant .
When is the VIM-2 the suitable product?	In Cryo due to its two-part design (no electronics remain on the sensor); in calibration because the sensor system is bakeable to 450°C .
How accurate and reproducible is the process?	High intrinsic accuracy of +/- 6% without factory calibration, +/- 1% with calibration; high long-term stability .
How does the system behave under the influence of magnetic fields?	Not affected by standard industrial magnetic fields due to strong shielding by the ferromagnetic housing .
Is CF the suitable flange?	CF is metal-sealed for high-end, expensive applications; it is removable via 6 bolts/nuts .
Why is the measurement method advantageous in calibration?	High absolute accuracy, no drift, and a known transfer standard .
Does the measurement system radiate magnetic fields into the process?	No; it is a self-contained magnetic system due to the ferromagnetic housing .
Is KF the suitable flange?	Elastomer-sealed for use up to 10^-7 mbar; easily removable with a simple clamp .
Can I sterilize the system?	Yes, it can be sterilized without problems (high-quality 316L stainless steel, simple geometry) .
Can I use the method in high-temperature applications?	Yes, the High-Temperature SRG is suitable up to 100°C; it is the only high-vacuum measurement device for these temperatures .
Is the Transducer the suitable product?	Yes, wherever integration is required; pre-set parameters (zero point/calibration factor) allow for Plug & Play .
Is a Tri-Clover flange the right solution?	Relevant for freeze-drying; available from us .
Can I measure Hydrogen?	Yes, Hydrogen can be used and measured .
Does online monitoring play a role for Transducers?	Relevant in Cryo for medical applications as well as liquid gas transport .
Is the weld-on stud the right solution?	Only for Cryo (main argument: longevity); minimizes leakage risk .
Why is the sensor not replaceable in Cryo?	The sensor should never leave the tube (fall out), even after decades; ultra-pure .
Why is absolute accuracy less relevant in Cryo?	Measurements occur across decades between 10^-5 and 10 mbar .
Do I have to set the zero point in Cryo applications?	No; intrinsic accuracy is sufficient for SRG resolution down to 10^-5 without a zero point .
Can I measure if tilted?	Yes, but at the expense of absolute accuracy .
Why is the method advantageous in Cryo technology?	High absolute accuracy, no influence on the vacuum, long lifespan, no drift, and a two-part system design .
Is there a 3.1 inspection certificate?	Yes, issued for material traceability and specifications .
How important is a 1-second response time?	Important in semiconductor processes; unimportant in Cryo, freeze-drying, and calibration .
How fast is the process?	1 second in Fast mode; generally 1-30 seconds depending on the pressure range .
Why is the method advantageous in the semiconductor industry?	High absolute accuracy/reproducibility, no process influence, long lifespan, and no drift .
Why is the method advantageous in degas chambers?	SRG can measure Hydrogen (which Ion Gauges cannot) and is insensitive to contamination/depositions .
Can an SRG correct an Ion Gauge signal in real time?	Yes, possible with a Booster .
Can an SRG semi-automatically adjust an Ion Gauge?	Yes, possible with a Booster .
How often must recalibration occur?	Technically never for non-condensable gases; ISO 3567 recommends once a year for references .
Is the calibration factor gas-dependent?	No (negligible) .
Is the process gas-dependent?	Yes—but only on the square root of the molar mass (well known) .
Is the process temperature-dependent?	Yes—but only on the square root of the temperature (well known) .
How can I avoid extremely strong condensation?	Use the High-Temperature SRG (100 degrees Celsius) .
How high is the accuracy without a zero-point adjustment?	Typical residual drag offset is 1 x 10^-5 to 3 x 10^-5 mbar .
How high is the accuracy without a calibration factor?	Maximum deviation of +/- 6% of the reading .
Does the system work with competitor sensors?	Yes—MKS, Spirotorr, Leybold (all with 4.5mm sensors) .
How high is the effort to replace Ion Gauges from various manufacturers?	The flange and Ion Gauge type must be known; installation time is maximum one hour (Plug & Play) .
How high is the risk when replacing an Ion Gauge?	No risk; 100% success rate .
What signals does the Transducer provide?	Modbus, ASCII (optional), LabView driver (optional), and Analog 0-10 VDC .
How hot can the sensor (sensor tube) get?	150°C with elastomer seals; 450°C with metal seals during bake-out .
Are there high-temperature gas friction manometers?	Yes, the High-Temperature SRG by PH Instruments (world first since 2025) .
What is the ideal measuring range?	10^-2 to 1 x 10^-6 mbar; 10^-4 to 10^-6 is our USP .
Can we measure below 1 x 10^-7 mbar?	No; only for experts .
What are the standard applications for SRGs?	Semicon Implant, Degas, Cryo, Vacuum Insulation, and Calibration.
How old is the technology?	Theory from the early 1970s; first prototype in 1976; commercialized in 1981; Transducers since 2019 .
What were the first applications of the technology?	Calibration (PTD) .
How does a Transducer differ from a laboratory SRG?	Transducers are autonomous and integration-optimized; VIM-2 offers easier 'one-button' mobile usage compared to manual lab units .
Do I have to adjust measurement times manually?	No, there is an adaptive mode available .
What response times are expected?	1, 3, 5, 10, 20, 30 seconds or adaptive; 1 second in Fast Mode .
How sensitive is the system to vibration?	Relatively insensitive due to a magnetic bearing twice as strong as other SRGs .
Is it ATEX certified?	No, but it is certifiable .
Why is the method advantageous in industrial PVD?	Ideal for the 2 x 10^-5 mbar starting point of these processes .
Why is the method advantageous in Dry-Etch?	High accuracy, no process influence, no drift (deposition-insensitive), and 100°C capable .
Why is the method advantageous in freeze-drying?	High accuracy, sterilisable, long-term stable, and no drift .
Why is the method advantageous in Ion Beam or Molecular Beam applications?	High accuracy, reproducibility, no process influence, and long lifespan .
What certification levels are offered?	SEL, CAL, DAkkS, and PTB.
Is there an electrical feedthrough?	No, there are no feedthroughs of any kind .
Are there more accurate reproducible measurement methods?	Not between 10^-4 and 10^-7 mbar.
What is the absolute accuracy?	Plus/minus 6% without calibration .
What is the reproducibility of the SRG?	No drift over time; < 1.5% per annum .
What is repeatability?	High accuracy (same readings across different process chambers).
What alternative pressure measurement methods exist?	Capacitive, Ion Gauges, and Pirani (Convection) .
How far apart can electronics and sensors be placed?	Maximum 5 meters.
How radiation-resistant is the system?	Electronics can be separated up to 5m (special 10m) for radiation-shielded areas ; stainless steel sensor parts are highly tolerant .
What advantage does a Transducer offer?	Plug & Play, pre-set, and measures autonomously .
Can I replace Ion Gauges 1:1?	Yes, if 1 second reaction time is sufficient between 10^-2 to 5 x 10^-7 .
What if a 1-second response time is not enough?	Use a Booster as a parallel measurement method for the Ion Gauge (in-situ calibration) .
What training is needed to operate a VIM-2?	Approx. 10 minutes or use the manual; none needed for Cryo (one-button usage) .
Do I need tools for evaluation unit installation?	No, the head is simply screwed on by hand .
What power supply do I need for a VIM-2?	24 Volt DC (via the included 100-240V AC power supply) .
Are there mobile gas friction manometers (battery-powered)?	Yes, the VIM-2 supports both mains and battery operation .
How long does a measurement take?	Between 1 and 30 seconds depending on uncertainty and pressure .
How is data saved?	.csv file via GUI; VIM-2 internal memory (1023 values with timestamp, pressure, temp) .
In what format is data exported?	.csv text format or Analog 0-10 Volt .
Is there operating software?	Yes, included as standard on a USB stick.
How long does a retrofit take?	About one hour .
How risky is a retrofit?	Risk-free.
What analog signals are provided?	0-10 VDC and 0-10 mVDC .
How high is the latency?	< 60ms for digital; 0 ms for analog output.
Why is there a high-temperature version of the SRG?	For sterilizability and to prevent condensation .
How many SRGs has PHI manufactured to date?	~600.
What are standard delivery times?	1-2 weeks, FCA Spittal an der Drau .
How expensive is a calibrated sensor system?	€1,200 - €2,200 for hardware + calibration .
How expensive is a recalibration?	Between €600 net and €1,300 net (DAkkS) depending on the standard.
How expensive is an inspection?	€400 net per component (includes scrapping fee) .
Is there an inspection certificate?	Yes, cost is €150 net.
What does the 3.1 inspection certificate cost?	€150 net .
Is the sensor system suitable for outdoor use?	Yes, all-metal stainless steel construction.
Does calibration change during a power failure?	No, negligible .
Are there retrofit promotions?	Yes.
Where can the SRG be used?	IG locations 1-3, degas, cryo/vacuum tanks, transport lines, Panels, LH2 filling stations, etc .
On which tools can it be used?	Implant tools, cluster tools (PVD/CVD), high-temp furnaces, sputter, industrial PVD, ion beam .
What accuracy do SRGs offer compared to Ion Gauges?	At least 20 times more accurate than new Ion Gauges; drift-free .
What durability do SRGs offer compared to Ion Gauges?	10 years+ for SRG; weeks to 1 year max for Ion Gauges .
What reproducibility do SRGs offer compared to Ion Gauges?	High reproducibility with no drift .
What material mix do SRGs have in the measuring cell?	Only stainless steel for SRG .
What linearity do SRGs offer compared to Ion Gauges?	100% linear for all gases; Ion Gauges require multi-point calibration for specific gases .
To what pressure range are SRGs 100% linear?	In the molecular flow range, < 10^-2 mbar .
What happens above this pressure range?	Compensated with feedback from the integrated temperature sensor .
Is there compensation? Which?	Sutherland compensation .
How does accuracy change above the linear range?	Accuracy changes steadily from 1% to 10% between 10^-2 and 10 mbar .
Why is SRG gas dependency low and compensable?	Only square root dependency; molar mass and temperature are well defined/measured .
Why is SRG temperature dependency low and compensable?	Only square root dependency; temperature is measured continuously in the head .
Do I have to set PHI SRG temperature compensation manually?	No, sensor is in the head .
Why are PHI SRGs insensitive to vibration?	Strong magnetic bearing (90 mT) and high rotation frequency (600 Hz) .
Where in an Implanter can SRG be used?	IG locations 1, 2, and 3 .
What advantage does SRG offer at IG1?	Reproducibility, accuracy (Chamber-to-Chamber match), no drift/contamination issues, early leak/outgassing detection, and replacement for obsolete controllers .
What advantage does SRG offer at IG2?	Same as IG1: high reproducibility, absolute accuracy, no drift or contamination issues, and designed for tool lifetime .
What advantage does SRG offer at IG3?	Avoids drift by referencing Ion Gauges via Booster technology; helps identify cryopump errors and reduces downtime .
What advantage does SRG offer at IG3 regarding Pressure Compensation?	Increases yield (1%+), improves wafer uniformity (up to 5%), and reduces wafer scrap (up to 100% reduction) .
Does usage at IG3 prevent wafer scrap?	Yes, through early detection of drift and recalibration of the stable Ion Gauge .
Does usage at IG3 prevent yield loss?	Yes, through early detection of drift and recalibration of the stable Ion Gauge .
Does usage at IG3 prevent tool down situations?	Yes, through early detection of drift and recalibration of the stable Ion Gauge .
Does usage at IG3 prevent unnecessary cryopump replacement?	Yes, as SRG referencing identifies drift so it isn't mistaken for actual pressure change .
Can usage at IG3 reduce downtime after Preventive Maintenance?	Yes, faster go/no-go checks .
Can usage at IG3 influence Ion Gauge lifespan?	Yes, through recalibration upon drift detection .
Can usage at IG3 influence Ion Gauge accuracy?	Yes, the accuracy is increased .
Which Implanter type (IG1) has the greatest need for SRG?	High-Current Implanters .
Which Implanter type (IG3) has the greatest need for SRG?	All with pressure compensation and batch tools .
What is the need at IG3 regarding cryopumps?	Accurate identifying of whether the problem is the gauge or the pump .
Can I connect an SRG via a T-piece or elbow?	Yes, without problems .
Can I connect an Ion Gauge via a T-piece or elbow?	No, it produces its own vacuum .
Which systems prefer the SRG Transducer?	Implanters, cryo-tanks, transport lines, containers, trailers, and PVD systems .
How long do Ion Gauges last on average?	2 weeks to 6 months; shortest in High Current applications .
Can the SRG Transducer replace obsolete Ion Gauge systems?	Yes, PH Instruments performs these Plug & Play replacements .
Can it replace obsolete 0-10mV Ion Gauges?	Yes, Plug & Play .
Is there a reference list for successful substitutions?	Yes .
Success rate of 1:1 replacement?	100% .
How long for an SRG Transducer retrofit?	Max 1 hour .
SRG lifespan in implants?	Tool lifetime .
Do I need valves to separate SRG from the chamber?	No, extremely robust .
Is the Transducer ARC-sensitive?	No .
Can it detect glitch effects?	Yes, has been used to select defective wafers .
Helpful for Advanced Process Control (APC)?	Yes, due to lack of drift, contamination, or failures .
Chamber-to-Chamber match?	Yes, due to high accuracy and reproducibility .
Detect leaks in an Ion Source (IG1)?	Yes .
Detect outgassing?	Yes.
Recognize MFC drift?	Yes .
Monitor hydrogen-containing process gases?	Yes .
Why use PHI VIM-2 over competitors?	Stronger magnetic bearing, user-friendly mobile operation, tool-free installation, and better magnetic shielding .
Difference in flanges vs competitors?	PHI offers all variants (CF40, weld-on, etc.), single-piece design, and mechanical protection .
DosiTorr connectivity?	USB-C, HD15, online monitoring .
DAkkS calibration time?	14 weeks.
Calibration types offered?	DAkkS, CAL, SEL, and PTB .
Calibration duration?	CAL/SEL 1 week; PTB 6-12 months .
Measure corrosive media?	Yes (BF3, PH3, etc.) .
Info transfer from sensor to device?	Inductive; no feedthrough or leak risk .
Does re-acceleration disturb continuous measurement?	No, takes ms.
Operational complexity?	VIM-2 is one-button; Transducer is autonomous .
Plug & Play replacement?	All Ion Gauges .
Does replacing capacitance manometers make sense?	Yes, below 10^-3 mbar or if contamination occurs .
Main application areas for process manometers?	Ion/molecular beam sources and coating processes .
Minimize boil-off effect?	Yes, via early detection in insulation vacuum .
Determine pressure without opening cryo vacuum?	Yes, minimizes risk with the two-part system .
Typical Ion Gauge problems?	Drift, aging, outgassing, and low lifespan .
Ion Gauge is too inaccurate?	Replace with SRG .
Ion Gauge calibrated for Nitrogen but I use other gas?	Replace with SRG due to low/defined gas dependency .
Ideal for 10^-5 mbar?	SRG .
High-Energy Physics?	Yes, up to 5 meters separation possible .
ROI for Implant?	Typically < 1 year .