BSI's family of Single-Channel Radiometers.Biospherical Instruments offers a variety of small, single-channel radiometers for use in the laboratory; deployment with profilers, CTDs, gliders, floats, and meteorological stations; use in aquaculture and biofuel plants; and for many other marine or terrestrial applications. The instruments are available in a large number of configurations with respect to spectral response, directional response, depth rating, signal output, packaging, cabling, and accessories.

Our Q-Series instruments measure Photosynthetically Active Radiation (PAR). Monochromatic instruments (M-Series) measure radiation in a narrow wavelength band, which can be selected from over 25 wavelengths in the UV and visible. Measurement geometries include cosine irradiance, scalar irradiance, and radiance. Depending on the model, measurements are outputted as either a digital data stream, or as "linear analog" or "logarithmic analog" signals.

A variety of our sensors have been interfaced with Sea-Bird CTD and data logging systems including the QSP, QCP, QSR, and QCR. Please consult Sea-Bird for the proper sensor selection.

Featured Sensor

BSI has recently introduced a new class of single-channel sensors for laboratory applications, called the Advanced Multi-purpOse Usb Radiometer (AMOUR). In contrast to Q- and M-Series sensors discussed on this page, the AMOUR sensor is based on microradiometer technology, and features a dynamic range of more than 10 orders of magnitude and a high-speed USB interface. The instrument is very versatile as the user can select different front-optics (e.g., scalar irradiance, cosine irradiance, radiance, and SMA fiber interface).

Selection Guide for Single-Channel Sensors

Overview

Q- and M-Series single-channel sensors are available in a large number of configurations. The following matrix provides an overview of the most commonly available combinations of features, and the associated model numbers. Models are identified by a three‐letter code followed by a four‐digit number. The different options are explained in detail below the matrix. Click on the model numbers for more information!

Series:	QSP	QSL	QSR	QCP	QCR	MCP	MCR	MRP
Spectral Response	PAR	PAR	PAR	PAR	PAR	Monochromatic	Monochromatic	Monochromatic
Collector	Scalar	Scalar	Scalar	Cosine	Cosine	Cosine	Cosine	Radiance
Environment/ Depth	2,000 m	Laboratory (QSPL 2,000 m)	Terrestrial	2,000 m, 6,800 m, 10,000 m. (Model dependent)	Terrestrial	2,000 m, 6,800 m, 10,000 m. (Model dependent)	Terrestrial	2,000 m
Digital binary output	QSP-2100	QSL-2100, QSL-2101, QSPL-2100, QSPL-2101	QSR-2100	QCP-2100	QCR-2100	MCP-2100	MCR-2100	MRP-2100
Digital ASCII output	QSP-2150	QSL-2150, QSL-2151, QSPL-2150, QSPL-2151	QSR-2150	QCP-2150	QCR-2150	MCP-2150	MCR-2150	MRP-2150
Linear analog Output	QSP-2200	QSL-2200 QSL-2201	QSR-2200	QCP-2200	QCR-2200	MCP-2200	MCR-2200	MRP-2200
Compressed analog output	QSP-2300 QSP-2350			QCP-2300 QCP-2350		MCP-2300		MRP-2300

Spectral Response, Collector, and Depth Options

• Spectral response: Two options (“Q” and “M”) are available: PAR or Monochromatic. All sensors are calibrated using standards of spectral irradiance that are traceable to the National Institute of Standards and Technology (NIST).
  
  • PAR sensors measure Photosynthetically Available (or Active) Radiation. Sensors are equipped with a proprietary combination of multilayer interference filters and absorbing glasses to achieve a near-constant quantum response between 400 and 700 nm.
  • Monochromatic sensors employ a narrow‐band multi-cavity interference filter with a bandwidth of approximately 10 nm. Additional absorbing glass filters are used to further reduce out-of-band response.
  • The spectral response is encoded in the first letter of the model designator, which is “Q” for PAR sensors (short for quantum response) and “M” for monochromatic sensors.
• Collector: Sensors can be equipped with three different collector types to measure either scalar irradiance, cosine irradiance, or radiance. 
  • Scalar irradiance collectors are insensitive to the direction of the incident radiation. The solid angle of acceptance is close to 4π (pi) steradians.
  • The sensitivity of cosine irradiance sensors varies with the cosine of the angle between the incident radiation and the normal vector of the collector. 
  • Radiance sensors have a field of view of typically 10°.
  • The collector geometry is encoded in the second letter of the model designator, which is “S”, “C”, or “R”, for scalar irradiance, cosine irradiance, and radiance, respectively.
• Environment / Depth: The third letter of the model designator is either “P”, “L”, or “R” and indicates the environment of operation. “P” specifies profiling underwater sensors used for continuous immersion. Maximum depths are 2,000 m, 6,800 m and 10,000 m, depending on model. The letter “L” is used for laboratory sensors, and “R” indicates reference above-water radiometers.

Output Options 

Most sensors are available as analog and digital output models. The four‐digit number following the three-letter model designator indicates the electrical interface of the sensor:

• Digital binary output (2100 series): a 24 bit analog-to-digital converter provides a binary output at a fixed sampling rate of approximately 4 Hz. Sensors are designed for use with “Logger 2100” software, which provides real-time display and data logging on a PC.
• Digital ASCII output (2150 series): the sensor uses a 24 bit analog-to-digital converter with low noise and excellent stability. Sampling rates range from 250 Hz to 1 sample average per hour. Output is provided as a calibrated ASCII text data stream with optional inclusion of sensor temperature. Sensor is designed for use with “Logger 2150” software but the data format is also ideally suited for integration with third-party software, for example, in multi-parameter monitoring systems.
• Linear-analog output (2200 series): the sensor features a high-quality, low-drift, electrometer-grade amplifier. Output is voltage (0‐5 V). A 16 bit or higher analog-to-digital converter is recommended for optimum performance. 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. Instead of a voltage output, a "direct-from-the-photodiode" current output is also available.
• Compressed analog voltage output (2300 and 2350 series): these sensors use a 24‐bit analog-to-digital converter to sample the signal, the logarithm is computed and the result is converted into an analog voltage (0‐5 V) that can be satisfactorily digitized by most data acquisition systems. This output configuration is particularly useful for users that acquire their sensor readings through a CTD or other data acquisition system equipped with a limited dynamic range.
• Multiple Instruments. Multiple digital output (2100 series) sensors can be connected together with a Biospherical Instruments DSM sensor multiplexer. Data from all sensors are logged via a single PC serial or USB port. Multiple sensors may be powered via the same USB port. Data rates depend on the number of sensors; for example a system with four sensors has a maximum data rate of approximately 3 Hz.

Connectors

• Left: LSG-4-BCL, Right: MCBH-5-F-SSDigital binary output (2100 series) underwater models (QSP-2100, QCP-2100, MCP-2100) use a SubConn MCBH5F bulkhead connector, which we rate to a maximum depth of 2,000 m.
• Digital ASCII output (2150 series) underwater models (QSP-2150, QCP-2150, MCP-2150) use a SubConn MCBH4M bulkhead connector, which we rate to a maximum depth of 2,000 m. 
• Analog output (2200 and 2300 series) underwater models use a LSG-4-BCL bulkhead connector, which is rated to a depth of 2,000 m.
• Surface reference sensors (QSR and QCR series) use a splash-proof Switchcraft EN3P5M connector.
• High-pressure (-HP) versions of the QCP series have several connector options:
  
  • Models QCP-2200-HP and QCP-2300-HP use a XSG-4-BCL-HP bulkhead connector, which is rated to a maximum depth of 6,800 m.
  • Model QCP-2350-HP uses a BH4M connector. The sensor is rated up to maximum depth of 10,000 m.

Additional Options

Additional features and options are available, including specialized spectral sensitivity (e.g., photopic and “blue light hazard” responses), specialized connectors, direct photodiode current output (option “-PD”), housings tailored for specific platforms (gliders), and extended operating depths of up to 10,000 m for cosine collector‐equipped sensors. Please contact sales if you cannot find the configuration most suitable for your application.

 

Detailed Sensor Descriptions

QSP Series

QSP sensor.

QSP sensors are designed to measure scalar irradiance with a PAR response in natural waters to depths of up to 2,000 m. Custom‐housed versions are available for gliders and other undersea or monitoring applications such as CTD profilers.

The QSP series comprises five different models with digital binary (QSP-2100), digital ASCII (QSP-2150), linear analog (QSP-2200), and compressed analog (QSP-2300, QSP-2350) output. The QSP-2100 and QSP-2150 models use SubConn MCBH series connectors. Standard versions of the QSP-2200 and QSP-2300 use a LSG-4-BCL bulkhead connector, which is rated to a depth of 2,000 m. To be compatible with the QCP series, also two other connector types are available:

• Models QSP-2300-HP use a XSG-BCL-HP bulkhead connector.
• Model QSP-2350-HP uses a BH4M connector.

Note that the depth rating of all QSP sensors is 2,000 m, because the scalar collector can only withstand pressures of less than 3000 psi. Chosing the XSG-BCL-HP or BH4M connector does not extend the instrument's depth rating. For greater depths, use either the QCP-2300-HP or QCP-2350-HP sensor.

Download overview brochure for QSP models

Download in-depth brochure for model QSP-2150

Download in-depth brochure for models QSP-2300 and QSP-2350

 

QSL Series

QSL sensor (left) and QSPL sensor (right).

QSL sensors measure scalar irradiance with a PAR response and are optimized for use in the laboratory. For example, the scalar irradiance collector (a solid sphere made of Teflon®) is connected to the main housing by a 25 cm stainless‐steel encased glass light pipe. Applications include measurements of scalar PAR in growth chambers, aquaria, or photosynthetrons.

The QSL series comprises 10 different versions, including four models with digital binary output (QSL-2100, QSL-2101, QSPL-2100, and QSPL-2101), four models with digital ASCII output (QSL-2150, QSL-2151, QSPL-2150, and QSPL-2151), and two models with analog output (QSL-2200 and QSL-2201).

Models with model numbers ending in "1" (QSL-2101, QSPL-2101, QSL-2151, QSPL-2151) use a small 1.25 cm (1/2”) diameter scalar irradiance collector while all other models use a collector with a diameter of 1.9 cm (3/4”). The smaller collector is suitable for measurements of PAR in vials or glass bottles with a narrow neck. Models with the larger collector offer a more uniform directional response.

Two connector and housing options are available:

• QSL models (QSL-2100, QSL-2101, QSL-2150, QSL-2151, QSL-2200 and QSL-2201) are splash resistant and equipped with an O‐Ring sealed black plastic body with an integral strain relieved, 1.6 m long cable. The connector is not designed to be submerged.
• QSPL models (QSPL-2100, QSPL-2101, QSPL-2150, and QSPL-2151) use an O‐ring sealed, hard‐anodized aluminum housing and a MCBH series water-proof connector. These sensors are rated for depth up to 2,000 m.

Additional information on QSL-2100 and  QSL-2200 models is provided here.

Download overview brochure for QSL and QSPL models

Download in-depth brochure for model QSL-2150

 

QSR Series

QSR with (left) and without (right) shield.

QSR sensors are surface reference radiometers to measure scalar irradiance from sunlight with a PAR response. These sensors are often used on ships during on-deck incubations, or while a QSP sensor is vertically profiling, for example, when mounted on a CTD. QSR sensors are equipped with a detachable field-of-view cutoff shield to limit its response to light from the upper hemisphere (2 π steradians). The photo shows two QSR versions with and without the shield installed.

The QSR series comprises models with digital binary output (QSR-2100), digital ASCII output (QSR-2150), and analog output (QSR-2200). All models are equipped with a Switchcraft EN3P5M connector.

Download overview brochure for QSR models

Download in-depth brochure for model QSR-2150

 

QCP Series

QCP sensor.

QCP sensors are designed to measure cosine irradiance with a PAR response in natural waters. Depending on model, maximum depths are 2,000 m, 6,800 m and 10,000 m. Custom‐housed versions are available for gliders and other undersea or monitoring applications such as CTD profilers.

The QCP series comprises models with digital binary output (QCP-2100), digital ASCII output (QCP-2150), linear analog output (QCP-2200), and compressed analog output (QCP-2300 and QCP-2350).

The QCP-2100 and QCP-2150 models use SubConn MCBH series connectors and are rated to 6,800 m. Standard versions of the QCP-2200 and QCP-2300 use a LSG-4-BCL bulkhead connector, which is rated to a depth of 2,000 m. High-pressure (-HP) versions have two connector options:

• Models QCP-2200-HP and QCP-2300-HP use a XSG-4-BCL-HP bulkhead connector, which is rated to a maximum depth of 6,800 m.
• Model QCP-2350-HP uses a BH4M connector. The sensor is rated up to maximum depth of 10,000 m.

Download in-depth brochure for model QCP-2150

Download in-depth brochure for models QCP-2300 and QCP-2350

 

QCR Series

QCR sensor.

QCR sensors are surface reference radiometers to measure cosine irradiance from sunlight with a PAR response. These sensors are weather resistant but not designed for immersion in water. QSR sensors are typically used on ships during on-deck incubations, or while a QCP sensor is vertically profiling, for example, when mounted on a CTD.

The QCR series comprises models with digital binary output (QCR-2100), digital ASCII output (QCR-2150), and analog output (QCR-2200). All models are equipped with a Switchcraft EN3P5M connector.

Most specifications of QCR models are identical to those of the QCP series. The largest difference is the collector of the sensor: QCR models are optimized for use above water while QCP models are designed for under-water use. A QCP sensor can be used above water, but the "cosine error" of the collector would be relatively large.

Brochures for QCR sensors are currently not avaialble, but most specifications are identical with those of QCP sensors.

Download overview brochure for QCP Models

Download in-depth brochure for model QCP-2150

Download in-depth brochure for models QCP-2300 and QCP-2350

 

MCP Series

MCP sensor.

MCP sensors are identical to QCP sensors, except that they use 10 nm wide monochromatic filters instead of a PAR filter. More than 25 filter wavelengths are available. Contact Sales for details.

Download overview brochure for MCP models

Download in-depth brochure for model QCP-2150

Download in-depth brochure for models QCP-2300 and QCP-2350

 

MCR Series

MCR sensor.

MCR sensors are identical to QCR sensors, except that they use 10 nm wide monochromatic filters instead of a PAR filter. More than 25 filter wavelengths are available. Contact Sales for details.

 

MRP Series

MRP sensors measure monochromatic radiance for underwater profiling applications. The sensors use 10 nm wide monochromatic filters, which can be selected from more than 25 filter wavelengths. These instruments are less common and no brochure is currently available. Contact sales if you are interested in this sensor.

 

Specifications

The following list is a subset of specifications. For complete specifications see brochures for each model.

Optical Specifications of PAR Sensors (Q-Series)
Bandpass: 400–700 nm (PAR) quantum response; flatness: ±10% in core wavelength range
Out-of-band Rejection: >10⁴
Calibration: calibrated following NIST procedures using Standards of Spectral Irradiance traceable to NIST.

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Optical Specifications of Monochromatic Sensors (M-Series)
Center wavelengths: filter-photodetector combinations are available between 320 to 875 nm
Bandpass: 10 nm FWHM
Saturating irradiance or radiance: per SeaWiFS recommendations, other levels upon request
Calibration: calibrated following NIST procedures using Standards of Spectral Irradiance traceable to NIST.

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Typical units
PAR scalar irradiance:  quanta/(cm² s)
PAR cosine irradiance:  quanta/(cm² s)
Monochromatic scalar or cosine irradiance:  µW/(cm² nm)
Monochromatic radiance:  µW/(cm² sr nm)

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Directional Response
Scalar irradiance error: < ±3% for incidence angles < 90°; < ±10% for incidence angles < 130°.
Hemispherical scalar irradiance error: < ±6% for incidence angles <85°; cutoff to 0 at 95°.
Cosine collector: <±3% for incidence angles < 65°; < ±10% for incidence angles < 80°.
Radiance field of view (FOV) in water: 10° half-angle.

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Output Characteristics

Binary Digital (2100 series):
RS-232 compatible; RS-232 to USB converter included
Cable lengths up to 350 m from PC
9600 baud, 8 data bits, 1 stop bit, no parity (9600,N81)
“Logger 2100” software for Windows included

ASCII Digital (2150 series):
RS-232 compatible; RS-232 to USB converter included
Cable lengths up to 350 m from PC
9600 baud, 8 data bits, 1 stop bit, no parity (9600,N81)
“Logger 2150” software for Windows included

Linear Analog (2200 series):
Positive output polarity
Maximum output voltage: 5V, other levels upon request
Output impedance: 100 Ω

Logarithmic Analog (2300 and 2350 series):
Positive output polarity
Minimum voltage to 5 V, proportional to logarithm of irradiance
Output impedance: 100 Ω

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Input Power Requirements
Digital output models (2100 and 2150 series): Power is supplied by the PC comport which must meet these specs:
          2100 series:  6-12.5 VDC, 2mA.
          2150 series:  6-15 VDC, <5mA.
      Biospherical supplies customized USB-RS232 adaptors that insure proper voltage is supplied to these sensors.

Linear-analog output (2200 models):  6–15 VDC at 2 mA
Logarithmic-analog output (2300 and 2350 models):  6–15 VDC at 5 mA

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Light Collector Materials
Scalar collector:  solid Teflon® sphere
Cosine collector:  machined acrylic
Radiance window:  clear acrylic

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Housing Materials
QSP, QSPL, QSR, QCP, and QCR series: hard black anodized T6061-T6 aluminum
QSL series: black acetal homopolymer resin (Delrin)