The HPQ-T sensor is designed specifically for liquid level
detection by non-contact methods in clear or very translucent pipes. The sensor is mounted on a pipe that is between
3 to 7mm or 8 to 13mm in diameter and features an infrared light beam that becomes refracted and undetectable by the receiver when the liquid is present. The device runs on 10-28 VDC, has a response time of 2 msec max, has Light Operate/ Dark Operate Selectable output functioning, and has a 100 mA NPN or PNP output. There is minimal malfunction when air bubbles or water droplets are present. The indicator light is easy to view even when the sensors are gang mounted as all the controls and adjustments are located on the back side.
Features and Benefits

  • Small compact size and non-invasive sensing make installation and height adjustment easy
  • Many products to select from – provides flexibility to user based on concerns
  • Thru scan principle where liquid refracts light beam -insures reliable detection
  • Infrared beam can help penetrate slurries and other solids with similar detection effect as water/liquid. This can be used in mixing sections of the process.
  • Light operate / dark operate selector switch provides output flexibility.
  • Indicator lamp is easy to view even when sensors are gang mounted

Usage Recommendation
The standard gain setting versions work with most liquids. The 25% gain reduction should be used when large quantities of bubbles are present or where mixing in chambers requires the sensor to be able to detect water/fluid, solids, and mixture of solids/fluids equally. We recommend that the prospective user evaluate their chemical combinations and mixing situations to determine which sensor works best before finalizing the specification for use

Catalog Listings
HPQ-T1 NPN Output, 8-13mm O.D. pipe use, standard gain setting for most applications.
HPQ-T2 PNP Output, 8-13mm O.D. pipe use, standard gain setting for most applications.
HPQ-T1-004 NPN Output, 3-7mmO.D. pipe use, standard gain setting.
HPQ-T2-005 PNP Output, 3-7mmO.D. pipe use, standard gain setting.
HPQ-T1-008 NPN Output, 8-13mm O.D. pipe use, 25% gain reduction from standard.
HPQ-T2-009 PNP Output, 8-13mm O.D. pipe use, 25% gain reduction from standard.
NPN Models PNP Models
Scanning Type Through Scan
Supply Voltage 10 to 28 V DC (ripple 10% max.)
Current consumption 25 mA max.
Usable Pipe see catalog listing chart
Standard detecting object Water Note 1
Repetitive detecting agency 1 mm max.
Operating Mode Light-operated/dark-operated selectable
(with L-On/D-On selector)
Detecting object: dark, Non-detecting object: light
Output Open collector of NPN transistor Open collector of PNP transistor
Response time 2ms max.
Light Source Infrared LED
Indicator Red “on” with detection
Ambient Light Incandescent 1000 lx max.
Operating temperature -10 ~ +55°C
Storage temperature -25 ~ +70°C
Humidity 35~85% RH (without condensation)
Insulation resistance 20 M min. (at 500 V DC)
Dielectric strength 1000 V A 50/60 Hz 1 minute
Vibration 10~55 Hz, 15 mm double amplitude, 2 hours in each direction of X,Y,Z
Shock 500 m/s2 (approx. 50g)
3 times in each direction of X,Y,Z
Sealing IP50 (IEC standard)
Mass Approx. 25g
Protection False pulse protection (20ms type), reverse polarity protection
Approvals-CE to be completed by end 2002
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