Sensors

Delphi incorporated a humidity sensor, ambient air temperature sensor, and glass surface temperature sensor into a convenient, direct pluggable package: the Delphi Integrated Dew Point and Glass Temperature (IDGT) Sensor. Mounted directly on the windshield behind the rear view mirror, this sensor provides measurement data from all three sensors to an automatic climate control system. The system uses this data to help prevent the formation of windshield fog by automatically selecting the appropriate heating, ventilation and air conditioning (HVAC) modes and controls.
 
 The relative humidity information is processed by signal conditioning electronics mounted with the capacitive sensing element on a circuit board. The temperature sensors use negative temperature coefficient technology. Dew point can be calculated using the relative humidity and ambient air temperature measurement by the automatic climate control system.

Benefits

• Conditioning electronics integrated with the sensing element
• Calculates an accurate measurement of relative humidity
• Compact size enables mass and cost reduction, reduces interfaces, and helps improve reliability
• Thermistor output allows for dew point calculation
• Improves driver visibility by helping prevent windshield fog
• Reduces driver active interaction by reducing the need to adjust HVAC controls
• Direct glass temperature measure improves system accuracy
• Robust sensing element with the ability to recover from 100 percent humidity and an operating range to +125°C, allowing applications in harsh environments
• Design and application flexibility with customized packaging of:
• Mounting features
• Sealing options
• Connection system
• Resistance output
• High resistance to temperature extremes and thermal shock
• Simplified assembly process
• Consistent performance characteristics
• Reduced performance variation

Typical Applications

Various markets, including:

• Automotive
• Appliance
• Industrial
• Medical
• Agricultural
• Environmental
• Process control

Performance Specifications

• Operating temperature: -40°C to +125°C
• Operating humidity: 0 to 100 percent RH
• Accuracy and interchangeability: ±6 percent RH from 10°C to 50°C and 20 percent to 90 percent RH, temperature ±1°
• Response time: 30 seconds in slowly moving air at 25°C maximum
• Output: serial (LIN bus)
• Typical voltage supply: 9 to 16 V DC
• Overall weight: 5.7 grams

Installation Diagrams for Delphi Integrated Dew Point and Glass Temperature Sensor

Note: All measurements are in millimeters.