The DAQ-U is a modular, radiometrically calibrated (with certificate) USB-C spectroradiometer. The integrated spectroradiometer records the changing ambient light spectrum (340 - 1010 nm) in irradiance (W/m²·nm) at up to 10 times per second (10 Hz), streaming live over its USB-C connection — no battery to charge and no memory card to manage. The DAQ-U contains the same radiometrically calibrated light sensor as our DAQ-M, with the same per-unit calibration support in Chloros.

Using Chloros with the DAQ-U you can stream live, radiometrically calibrated measurements to your computer over USB-C. Chloros automatically downloads each DAQ-U's unique radiometric calibration from MAPIR Cloud and applies it to every measurement — including the correction profile for the installed cap — so your data is always in absolute irradiance (W/m²·nm). The live data can then be used with LATTICE cameras for real-time reflectance measurements. You can also record the data to a .daq file to be used in Chloros for processing Survey3 and LATTICE images.

Building your own recording setup? Our free, open-source Chloros Scripts (Python, MIT licensed) let you record raw DAQ-U measurements over USB-C to a .daq file from your own computer or embedded device. Note that the scripts record raw (uncalibrated) data only — Chloros is still required to apply each unit's radiometric calibration and process the data.

Main Features:

Research-grade spectrometer with absolute power calibration (W/m²·nm)
Radiometric calibration certificate provided with every unit (download using Chloros)
Automatic radiometric calibration in Chloros: each unit's unique calibration (gain, dark offset and cap correction) is downloaded from MAPIR Cloud and applied to every measurement — even raw recordings are calibrated automatically at processing time
Streams over USB-C at up to 10 Hz: no battery to charge, no internal memory to download — plug into any Windows or Linux computer (including embedded devices) and start measuring
Open-source recording scripts: record raw DAQ-U data over USB-C using our free Python scripts (MIT licensed) — ideal for custom and embedded setups. Scripts record raw data only; Chloros is required to calibrate and process it.
Six optional caps (available as a 6 pack): the white glass cosine corrector "Sunshine" cap for ambient/downwelling light, plus five field-of-view caps (15°, 30°, 45°, 60°, 90°) for measuring reflected light. Chloros automatically applies the matching cap correction profile, and assumes the Sunshine cap is installed by default.
Optional tripod mount: a convenient way to mount the DAQ-U, adding a standard 1/4-20 tripod thread
Two main measurement modes:
- Irradiance = records changes in the ambient light spectrum, used to produce multispectral reflectance images in Chloros.
- Reflectance = records irradiance measurements of MAPIR reference targets and objects of interest, used to measure live reflectance in Chloros.
With a large spectrum coverage (340 - 1010 nm) you only need one DAQ-U to support calibrating every model of Survey3 and LATTICE camera we offer. A single log file can correct any number of cameras.
Device-to-device repeatability
Durable and reliable: no moving parts
Never needs to be recalibrated
Wide operating temperature range
Auto exposure and frame averaging control

DAQ-U Measurement Capability:

MODE	UNITS	DESCRIPTION
Spectro-radiometer	Spectral Irradiance Power (W/m²·nm)	Research-grade spectroradiometer with absolute power calibration. Commonly used for recording the ambient light spectrum to correct multispectral images. Can also be used for measuring object irradiance, to be later post-processed into percent reflectance.
Spectro-photometer*	Percent Reflectance (%)	Research-grade spectrophotometer output by post processing raw irradiance data. Commonly used to measure object reflectance. Directly compare with pixel reflectance obtained from processed multispectral images.
Irradiance Sensor	Total Irradiance Power (W/m²)	Measure total power output of the ambient light across the sensor's entire range (340-1010nm).
Colorimeter	CCT (K), CRI, XYZ, xy, uv	Accurate color data based on spectrometer measurement (superior to filter-based colorimeters).
PAR Light/ Lux Meter	Photometric Illuminance (lm/m² = lux), PPFD (µmol/m²/s)	Assesses light levels relevant to plant growth (Photosynthetic Active Radiation - PAR, measured as PPFD) and human visual perception (Photometric Illuminance, measured as Lux). Essential for applications in horticulture, general lighting design, and assessments of light intensity on surfaces.

* requires a measurement scan from the white target in our calibration packages.

DAQ-U Measurement Example (recorded in Chloros):

Every .daq recording is self-describing: the file stores the device model, serial number, installed cap and the exact per-unit calibration that was applied, along with the values below for every measurement.

NAME	UNIT	VALUES
Device Model		DAQ-U
Sensor ID		CB-74-02-34-9B
Cap		Sunshine (Cosine Corrector)
Calibration		Applied (per-unit calibration ID and date stored in file)
Timestamp	UTC (nanosecond precision)	2025-04-23 13:39:14
Is Saturate	yes, not	not
Integration Time	ms	32
Frame Average	frames	20
Wavelength	nm	340, 345, 350, ... 670, 675, 680, ... 1000, 1005, 1010
Spectrum	W/(m²·nm)	0.028496599, 0.026482204, 0.023346003, ... 0.056949656, 0.056615341, 0.056946527, ... 0.026041711, 0.025839653, 0.025660584
PPFD Spectrum	µmol/m²/s/nm	0, 0, 0, ... 0.318986416, 0.31948036, 0.323729604, ... 0, 0, 0
Total Power	W/m²	33.37362
Photopic Lux	lumen/m²	4794
Scotopic Lux	lumen/m²	11506
S/P Ratio		2.40
S-cone-opic	lumen/m²	3978
Melanopic	lumen/m²	4386
Rhodopic	lumen/m²	4485
M-cone-opic	lumen/m²	4723
L-cone-opic	lumen/m²	4872
PPFD	μmol/m²/s	87
PPFD-R	μmol/m²/s	34
PPFD-G	μmol/m²/s	33
PPFD-B	μmol/m²/s	23
CCT	Kelvin	5484
Duv		0.0048
CRI		99
Dominant Wavelength	nm	571
Peak Wavelength	nm	675
Excitation Purity		0.031
XYZ		4557, 4794, 4339
xy		0.3329, 0.3502
uv		0.2037, 0.4822
CIELAB (L, a, b*)		97.6, -2.1, 3.4
Munsell (H V/C)		5Y 9.6/0.8

DAQ-U Caps and Mounting (Optional):

The DAQ-U is modular by design. Six snap-on caps — available as a 6 pack, which includes the Sunshine cap — let you configure the sensor for your measurement. Simply select the installed cap in Chloros and the matching correction profile is automatically applied to your data.

Chloros assumes the Sunshine cap is installed by default, as ambient light measurement with the Sunshine cap is the most common measurement method. If you are using a different cap (or no cap), select it in Chloros to ensure accurate power readings.

CAP	WEIGHT	DESCRIPTION
Sunshine Cap (White Glass Cosine Corrector)	1.09 g	The main cap most users will need — and the cap Chloros assumes is installed by default. The white glass cosine corrector diffuses incoming light for accurate ambient/downwelling irradiance measurements, such as bright direct sunlight. Use it when recording the ambient light spectrum to correct Survey3 and LATTICE multispectral images for percent reflectance.
90 Degree Cap	1.09 g	Restricts the sensor's field of view to 90° for measuring light reflected from objects and reference targets.
60 Degree Cap	1.15 g	Restricts the sensor's field of view to 60° for measuring light reflected from objects and reference targets.
45 Degree Cap	1.17 g	Restricts the sensor's field of view to 45° for measuring light reflected from objects and reference targets.
30 Degree Cap	1.21 g	Restricts the sensor's field of view to 30° for measuring light reflected from objects and reference targets.
15 Degree Cap	1.21 g	Restricts the sensor's field of view to 15° — the narrowest field of view, for the most selective object and reference target measurements.

Reflected-light (field of view cap) measurements can be calibrated for percent reflectance using a scan of the white target in our calibration packages.

The optional DAQ-U Tripod Mount (7.43 g) is a convenient way to mount the DAQ-U: it attaches to the DAQ-U to add a standard 1/4-20 tripod thread for stationary measurement setups, such as lab benches, field stations and lighting assessments.

DAQ-U Power and Connectivity

The DAQ-U is powered directly over its USB-C connection — there is no battery to charge and no internal memory to manage. Plug it into any Windows or Linux computer (including embedded devices) and stream measurements live using Chloros or our open-source Chloros Scripts.

DAQ-U Specifications:

Dimensions (without cap)	36 x 20 x 12 mm (1.4 x 0.8 x 0.5 in) (L x W x H)
Dimensions (with cap)	42 x 20 x 12 mm (1.7 x 0.8 x 0.5 in) (L x W x H)
Weight	8.13 g (9.22 g with Sunshine cap)
Memory Storage	None (Streams Over USB-C)
Power	USB-C (No Battery)
System Time Sync	Host Computer Clock
Interface	USB-C (USB Serial)
Software	Chloros (Windows, Linux), Open-Source Python Scripts
Operation Temperature Range	0C - 60C (32F - 140F)

Spectrometer Calibration	Radiometric (W/m²·nm)
Calibration Certificate	Per-Unit PDF (Downloaded via Chloros)
Wavelength Range	340 - 1010 nm
Number of Measurements Recorded	135
Wavelength Measurement Width	5 nm
Wavelength Resolution	20 nm - 50 nm
Wavelength Accuracy	3 nm
Repeatability (peak)	1 nm
Measurement Power Range	20 - 150,000 Lux (PPFD: 0 -2,000 μmol)
Measurement Period	Integration Time x Frame Averaging (+ ~10 ms USB overhead)
Signal to Noise Ratio	250 : 1 @ Max. Power & Average of 40
Dynamic Range	> 1000 : 1
Linearity	99%
Integration Time	Auto, or Manual (4 ms - 500 ms)
Streaming Rate (Maximum)	~10 Hz (adjustable via integration time and frame averaging)
Diffuser	White Glass Cosine Corrector (Optional Sunshine Cap)
Field of View	<180 degrees (Sunshine Cap); 15° / 30° / 45° / 60° / 90° (FOV Caps)

Included:

1 x DAQ-U spectroradiometer

1 x USB-C cable (1m)

1 x Radiometric calibration certificate (digital, downloaded via Chloros)

Caps and tripod mount sold separately.

DAQ-U

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