Single Channel Sensors
(PAR and Monochromatic Sensors)

Biospherical's family of single-channel, analog-output sensors includes versions that will fit almost any marine or terrestrial application. Sensors are available in a variety of geometries to measure radiance, scalar irradiance, and cosine irradiance, and are available over the visible to near-infrared spectrum.  They are available in both monochromatic (M-Series) and PAR (Q-Series) versions.  Versions are available outputting a serial digital data stream, linear analog, or logarithmic analog signals.

Product Descriptions

  • QCP - MCP Cosine Irradiance sensors are used on CTD/STD profilers to add measurements of downwelling irradiance to the data stream.  Available with either a linear or logarithmic analog (voltage) output, or with digital data output. 

  • MRP  Radiance sensors are used on CTD/STD profilers to add measurements of upwelling radiance to the data stream.  Available with either a linear or logarithmic analog (voltage) output, or with digital data output. 

  • QSP - MSP Scalar Irradiance sensors are often used on CTD/STD profilers to add measurements of light independent of the angle of incidence.  They are available with either a linear or logarithmic analog (voltage) output, or with digital data output. 

  • QSL Laboratory Scalar Irradiance sensors provide general purpose measurements of light in applications such as growth chambers, aquaria, or photosynthetrons. 

In general, the QSP-, QCP-, MCP-, and MRP-series of instruments are designed to meet the need for  small, rugged, low power light sensors useful for integration on CTDs or other profiling packages.  Submersible sensors are specified to an operating depth of 2000 meters, although the QCP series are rated to 10,000 meters when equipped with a high-pressure connector.  The redesigned QSL-series laboratory light sensor is now entirely integrated into the handle.  Fitted with an underwater connector, the QSPL model of the QSL is fullly submersible.    QSR and QCR surface reference sensors are weatherized to withstand rain or snowfall.   We manufacture over 20 varieties of single-channel sensors.   The table below lists the wide variety of sensors that are available. The sensors are grouped by the geometry of the measurement; model numbers are grouped by the output type (digital, analog, or log).

Click here to view a comparison of single-channel sensor characteristics

Qseries.jpg (20150 bytes)Depth Capability.  The standard deployment depth for QSP, QCP, MCP, and MRP series sensors is 2,000 m.  When equipped with a high pressure connector, QCP-series sensors may be deployed to 10,000 m.  QSR and QCR-series surface reference sensors are designed for terrestrial use and are sealed for weather-resistance.   QSL sensors are splash resistant and are not submersible.  QSPL laboratory sensors are fully submersible. 

Spectral Response.  PAR sensors are equipped with a proprietary combination of multi-layer interference filters and absorbing glasses to achieve a near-constant quantum response.  Monochromatic models employ proprietary filtered-photodetectors in which a multicavity interference filter is mounted with the photodetector in a hermetically sealed package.  Additional absorbing glass filters are used to further reduce out-of-band response, which can cause unwanted measurement and calibration artifacts.  All sensors come calibrated to standards of spectral irradiance, traceable to the National Institute of Standards and Technology (NIST).

Output Options.  THERE ARE THREE OUTPUT OPTIONS.  

  1. Digital output (2100 series) sensors provides a direct serial data connection to a PC for both real-time display and logging.
  2. Linear analog output (2200 series) models feature high-quality, low-drift, electrometer-grade amplifiers (positive polarity is standard).   Normally, SeaWiFS guidelines are used to set the saturating irradiance or radiance values for a sensor, although a wide range of levels is available upon request.   Direct-from-photodiode current output is also available for all 2200 sensor types.
  3. Logarithmic output (2300 series) sensors are particularly useful for users that acquire their sensor readings through a CTD or other data acquisition system equipped with a limited dynamic range.   These sensors rely on a high-quality, industry-standard, log amplifier to produce an output that varies over three to four orders of magnitude range.  

 

 

Multiple Instruments.  Multiple digital output (2100) sensors can be connected together with a Biospherical Instruments DSM sensor multiplexer. Data from all Multi-lr.jpg (44933 bytes)sensors are logged via a single  communications port of nearly any personal computer running Windows® (versions 98 through XP are supported).  All sensors are powered via the same communications port.  Data rates depend on the number of sensors; for example a system as pictured to the left with four sensors has a maximum data rate of a bit over 3 Hz.  Statistics such as the minimum, maximum, average, and sum of squares are recorded for each sensor.

 

Options

Lowering Frames  QSP-2210 Lowering Frame and Clamp for the Individual Q-Series Sensors

Specifications
Spectral Characteristics

Monochromatic Sensors

  • Center Wavelength Range: filter-photodetector combinations are available between 320 to 875 nm
  • Bandpass: 10nm FWHM ± <2 nm, approximately 20 nm for Natural Fluorescence (LuChl)
  • Center Wavelength accuracy: ±<2 nm
  • Out of Band Rejection (10 nm sensors): >104, 20 nm from center wavelength

Quantum PAR Sensors

  • Bandpass: 400 to 700 nm (PAR)
  • Flat  (±10%) Quantum Response
  • Out of Band Rejection: >104

Calibrations All units are calibrated following NIST procedures and using Standards of Spectral Irradiance traceable to NIST. Typical units:

  • Monochromatic Radiance:  µW/(cm2 · sr · nm)
  • Monochromatic Scalar or Cosine Irradiance:  µW/(cm2 · nm)
  • PAR Scalar Irradiance:  µE/(cm2 ·sec)
  • PAR Cosine Irradiance:  quanta/(cm2 ·sec)

Directional Response

  • Radiance field of view (FOV) in water 10° (1/2 angle)
  • Scalar irradiance error ±7% over a range of ±135° zenith angle
  • Hemispherical scalar error ±6%, over a range of ±85° zenith angle, cutoff to 0 at 95°.
  • Cosine collector: ±0 to 65°, ±3%, ±65 to 86°, ±10%

Output Characteristics

Digital (2100) Models

  • RS-232 Compliant
  • Cable lengths up to 350 m from PC!
  • 9600 baud, 8 data bits, 1 stop bit, no parity (9600,N81)
  • Software included (Windows 95, 98, 2000, NT, XP, and ME)

Linear Analog (2200) Models

  • Positive Output Polarity
  • Maximum Output Voltage: 5V, other levels upon request
  • Saturating Irradiance Linear Models: per SeaWiFS recommendations, other levels upon request
  • Maximum Noise Sensor Dark: <100 µV RMS
  • Dark Offset: <1mV
  • Output Impedance: 100 ohms

Logarithmic Analog (2300) Models

  • minimum voltage to 5V,  proportional to log of irradiance

Input Power Requirements:

  • 2100 digital output models: supplied by PC serial port
  • Linear analog output (2200 models):  6 to 15 VDC at 2mA
  • Logarithmic output (2300 models):  6 to 15 VDC at 100 mA
  • Photodiode current output:  none required

Light Collector Materials

  • Scalar collector:  solid Teflon® sphere
  • Cosine collector:  Machined Acrylic
  • Radiance window:  Clear Acrylic

Housing Materials:

  • Surface Scalar Reference (QSR-2000 Series): Hard black anodized T6061 Aluminum
  • Surface Cosine Reference (QCR-2000 Series): polyethylene terephthalate (PET) plastic
  • All standard marine series: Hard black anodized T6061 Aluminum and PET plastic

 

 

Single Sensor BrochureClick here to download a copy of the brochure for QSP single channel sensors.

Single Sensor BrochureClick here to download a copy of the brochure for QSR single channel sensors.

Single Sensor BrochureClick here to download a copy of the brochure for QCP single channel sensors.