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A Combined Pressure and Temperature Sensor without external temperature probe. Content. (1) Key P/T Sensor Specifications (2) Patented Thin Film Technology (3) Sensor Design for CO2 / R744 MACS (4) Finite Element Modeling / Simulation (5) Qualification Testing
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A Combined Pressure and Temperature Sensorwithout external temperature probe
Content (1) Key P/T Sensor Specifications (2) Patented Thin Film Technology (3) Sensor Design for CO2 / R744 MACS (4) Finite Element Modeling / Simulation (5) Qualification Testing (6) Other Thin Film Applications and Sensor products
(1) Key P/T Sensor Specifications • Pressure:Measurement Range 0 to 170 BarAccuracy < ± 1,0% (F.Sp.)Response time ~4 ms (t63) • Temperature:Media -40°C to +180°CAccuracy ~ ± 3 KResponse time < 10 sec (t63)Ambient Temperature up to 135°C • Electrical Interface: 3-pin LIN2.0, 3-pin PWM, 4-pin P/T analog
(2) Patented Thin Film Technology • Thin Film Element on SST • Sputtered Metal Strain Gauge • TiON Strain Gauge with high K-Factor/ Gauge Factor: K: TiON ~ 5 (CrNi ~ 1,1..2)K-Factor: dR/R= K * dl/l • High Temperature Resistance (330°C) • Pressure Range: 10 to 3.000 Bar 6 mm
(3) Sensor Design for CO2 / R744 MACS • Digital output: LIN2.0 or PWM(Temperature output embedded in signal) • Integrated Temp. feature: Less part complexity, higher reliability, less flow restriction and reduced leakage risk. • Long term stability, Rugged Design. • Smallest possible thread interface: M10x1mm
Connector Flexwire Component board with µC Housing Flexwire DV Chip Combined Sensor Assembly (p,T) p,T Exploded View / Cross Sectional
Kavlico DV Chip Dual Frequency-Output ASIC for Thin-Film and PRT Resistive type sensors: • Ratiometric multiplexed frequency (digital) output for Sensor (Pressure-) and Temperature-data. • Coarse gain and offset calibration via serial-interface, allowing wide range of sensors. • Fine calibration by µP ; calibration coefficients to be stored in memory of µP. • Extreme temperature range ( -50ºC to +200ºC ). • Low-Power (sleep mode and 3mA operational current) • Self-diagnostics and failure analysis.
Bumps on DV Chip Electrical Contact Underfill Adhesive Bridge pads DV Chip placement on Thin Film Flexure • Accurate Temperature measurement independent from ambient temperature. • Digital, non-susceptible output (temperature output embeded in signal).
Schematic Conditioning(PC Board) Sensing(Sensor assy) p T Micro Controller Flexwire Inter-connection DV chip Thin Film Strain Gauge LIN2.0 Transceiver Out
The influence of DV chip on the stress distribution and deflection of diaphragm is small r R Condition: 180ºC temperature, 150 bar pressure Effect of Chip on Diaphragm Stress and Deflection
Ambient Conditions: • 25ºC still air • 150ºC still air150ºC air flow / 4.4 m/s • 135ºC still air Thermal AnalysisImpact to electrical Components (PCB) CO2 @ 200 kg/h and 180ºC or 165ºC
Temperature Distributions after 5 Min. (25ºC Ambient Temperature) 25°C, Voo = 0m/s Printed Circuit Board 112~140ºC Initial Fluid Temperature: 25ºC; Transient to 180ºC
b) Temperature Distributions after 5 Min. (150ºC Ambient Temperature) 150°C, Voo = 4.4m/s 150°C, Voo = 0m/s 166~172ºC 167~173ºC Printed Circuit Board Initial Fluid Temperature: 25ºC; Transient to 180ºC
Replace PCB ULTEM 2310 PolyetherimidePlastic Connector Circuit Board Stainless Steel 304L Mount the circuit board to components with low thermal conductivity (plastics) away from the metal housing.
c) Design at 135ºC Ambient Temperature CO2 Temperature Printed Circuit Board Temperature 141-144ºC 5 min of 180ºC 5 min of 165ºC 139-141ºC Initial Fluid Temperature: 135ºC; Transient to 180ºCand165ºC
Conclusions • DV chip has negligible influence on the performance of sensor diaphragm / pressure sensor functionality. • By connecting the circuit board to plastics and away from the metal housing, the circuit board temperature can be reduced to around ~ 140ºC under 135ºC ambient Temperature
(5) Qualification Testing • Leackage test Requirement <1,0 gram per year The test is carried out at an external test lab, specialized on these kind of tests. • Design validation test on sensor levelStart after sample build in July 2008 Duration appr. 6 month.
(6) Other Thin Film Application and Sensor Products: • Direct Fuel Injection / Common Rail • In-Cylinder Pressure • Transmission / Break Pressure • Compressed Natural Gas (CNG) • Traction Control • (Mobile) Hydraulic Pressure / Controls • HVAC / Hydraulic Machinery
Contact:Mr. Markus ButenopDirector of SalesKAVLICO GmbH Potsdamer Str. 1432423 Minden GermanyPhone: +49 (0)571 3859 – 171Fax.: +49 (0)571 3859 – 119Email: mbutenop@kavlico.deWeb: www.kavlico.de / www.cst-sensors.com