ULM-500 Light Meter & Logger
Version:
Universal Light Meter & Data Logger
The ULM-500 is a fast light meter / data logger with a high dynamic range and adequate optional PAR-sensors for independent PAR-measurements, PAR-monitoring or automated light list calibration of WALZ devices.
Our data logger and sensors are capable of resolving the saturating light pulse of PAM Chlorophyll Fluorometers or fast light flecks in nature.
General Features ULM-500
Light Measurement
The main purpose of the ULM-500 is light-measurement. The ULM-500 has two connectors for light sensors with BNC plugs. Typically, PAR sensors and pyranometers are linked to the ULM-500. PAR sensors measure the flux of quanta (unit, μmol m-2 s-1) in the photosynthetically relevant wavelength range, that is, between 400 and 700 nm. Pyranometers detect the power of radiation (unit, W m-2) mostly in a wider spectral range so that solar radiation arriving at the Earth’s surface can be measured. When power of radiation is measured, a flux of short-wavelength (e.g. blue) photon results in a higher signal than the same flux of photons with longer wavelengths (e.g. red) simply because the former flux carries more energy than the latter.
The higher energy in blue than in red photons, however, is unavailable for photosynthesis so that photon fluxes as they are measured by PAR sensors are important for photosynthetic studies. We offer three different PAR-sensors suitable for use in conjunction with the ULM-500. Please find more information on sensors by clicking here.
Dynamic Range
The ULM-500 has 5 sensitivity ranges with fast automatic switching. As a result it has a high dynamic range reaching up to 99 999 μmol m-2 s-1 and may detect signals down to 0.1 μmol m-2 s-1 – even with the smallest sensor we offer. The range-switching can be set to automatic for convenient measurements or to manual for fast time resolution.
Time Resolution – Chart Mode
Channel no. 1 of the ULM-500 is optimized for high time resolution. In the chart mode a time course of 1.2 s (or 2.4 s) is shown, which contains 120 data points (max. 100 Hz). The minimum, maximum and average are indicated. With the triggered chart function a saturating light pulse changing from dark to several thousand μmol m-2 s-1 can be resolved. This is usually not possible with standard light meters. The ULM-500 can be connected to the software WinControl-3 for continuous fast recording of light flecks.
Data Storage
The ULM-500 can be used as simple light meter for single light measurements or as data logger for continuous measurements. It can store up to 50 000 data points. Stored data can be downloaded with the software WinControl-3.
Connectors
The ULM-500 has two BNC-connectors for light or PAR-sensors. Furthermore it has one connector for the Monitoring Leaf-Clip JUNIOR-B (Gen.1, analogue version), which can also be used to connect the Leaf-Clip 2030-B via an additional adapter (not compatible to 2035-B).
With the leaf clips not only PAR but also leaf temperature is measured, recorded and displayed.
Operation
The ULM 500 can be operated with its internal batteries or power can be supplied via USB-connector. Display illumination with white LED backlight renders readability in the dark. The ULM-500 is a stand-alone instrument, but can also be connected to a computer and operated with the software WinControl-3. Storage of several sensor calibration data is possible (10 different calibration values with probe names via WinControl-3 software).
The ULM-500 can continuously measure values triggered by an internal timer. For this purpose no additional computer is necessary.
To save battery power, the instrument has a "sleep mode", i.e. it only wakes up briefly for each measurement.
Using the ULM-500 for a continuous measurement (e.g. one data point every 5 min), the batteries would last for at least 3-4 months (depending on the temperature conditions).
For some of our PAM instruments, we provide sensors for the light-list calibration or for light and temperature measurements during an experiment. If just these sensors shall be used, it can be advantageously to have a small separate instrument like the Universal Light Meter ULM-500 to readout these sensors independently of a PAM.
In combination with the IMAGING-PAM system the ULM-500 can be used for calibration purposes and the recording of the incident light during the experiment. Additionally the ULM-500 is fast enough to determine the intensity of the saturating light pulses.
Since the ULM has two BNC connectors that can be used for parallel data acquisition, it is also possible to use the instrument for a continuous calculation of an attenuation index by using two identical PAR sensors above and below a sample. Another option is the comparison of the characteristics of two different sensors (for example PAR and photometric sensors).
ULM-500 Light Meter & Logger
Light grey plastic housing with connectors, membrane keyboard and a white illuminated LCD graphic display
12 x 7.5 x 3.5 cm
210 g (including 4 AAA 1.5 V batteries)
4 AAA-type batteries or 5 V DC from USB voltage source when connected to the computer
up to 85 % rH (avoid condensation), - 20° to + 50°C ambient temperature
PAR channel #1: 100 samples / second, PAR channel #2 and other channels: 5 samples / second (connected to computer running WinControl-3 software)
10 days or ca. 100 days automated logging with sleep mode (1 meas. / 5 min). Unlimited working time via USB connection (PC-software WinControl-3 – no sleep mode)
- Two BNC-connectors for the connection of two PAR-sensors with individual calibration factors between -50.0 and -9999.9 (memory for 10 calibration factors), range switchable in 5 steps 250 nA to 0.6 mA
- Connector for Monitoring Leaf-Clip JUNIOR-B; an adapter is available for the connection of the Leaf-Clip Holder 2030-B, and the Micro Quantum/Temp.-Sensor 2060-M
- Connector for additional digital sensors (still under development)
- USB-Connector for connection with computer (software: WinControl-3)
Flash memory used as ring buffer for 50000 lines (1 line / single measurement)
White illuminated graphic display with 5 different display modes (1: all data; 2-4: two selected sensors in big letters; 5: chart mode for channel no. 1, with maximum, minimum and average indicated), resolution: 0.1 μmol m-2 s-1
1 free USB socket. Processor, 1 GHz. RAM, 256 MB. Hard disc space, 20 MB. Screen resolution: 800 x 600 pixels. Interface, USB 1.1, 2.0 and 3.0. Operating system: Microsoft Windows 10 and 11.
Mini quantum sensor for selective PAR (photosynthetically active radiation) measurement, cosine corrected for PPFD (photosynthetical photon flux density) measurement.
Black anodized aluminum housing
Perspex
High stability silicone photovoltaic detector with filter set for PAR correction (to learn more about the typical sensitivity see “General Features”). Signal output typically -2 μA / (1000 μmol m-2 s-1)
0.01 %/K
± 5 %
error < 4 % between angles from -80° to +80° from normal axis
Typically 1.32
- 5 °C … + 45 °C
3 m
BNC
Not required
Height: 16 mm
Diameter: 14 mm
Diffuser diameter: 5.5 mm
32 g
WinControl-3 System Control and Data Acquisition Program (Microsoft Windows 10 and 11) for operation of measuring system via PC, data acquisition and analysis. Not compatible with Windows 10 on ARM
Measured: Ft, F0, FM, F, F0’ (also calculated), FM’. Depending on the leaf clip connected, the software can record PAR, temperature and also humidity. [In the case of the MINI-PAM-II clip humidity can be measured, which the clip of the JUNIOR-PAM cannot.]
Calculated: F0’ (also measured), FV/FM and Y(II) (maximum and effective photochemical yield of PS II, respectively), qL, qP, qN, NPQ, Y(NPQ), Y(NO) and ETR (electron transport rate)
Two routines for determination of the cardinal points α, Ik and ETRmax of light curves
Automatic determination of signal offset for all light intensities and gain levels. Automatic calibration of internal PAR sensor against an external PAR sensor connected to the instrument
Processor: 0.8 GHz, RAM: 512 MB, screen resolution: 1024 x 600 pixels, interface: USB 2.0/3.0
USB
Accessories
Small versatile waterproof mini quantum sensor for selective PAR measurement, cosine corrected for light incident at an angle between -30 ° to +30 ° from surface normal for PPFD (photosynthetical photon flux density) measurement, with base plate for screw connection.
Black resin material
Perspex
High stability silicone photovoltaic detector with filter set for PAR correction (see “General Features” for typical response)
0.01 %/K
BNC
Base plate: 12 mm x 7 mm x 1 mm (H x W x L)
Sensor housing 5 mm x 7.5 mm x 7 mm (H x W x L)
Diffuser diameter: 3 mm
26 g
Microscopy quantum sensor for PPFD (photosynthetical photon flux density) measurement.
Black anodized aluminum housing
Resin with fluorescence dye
High stability silicon photovoltaic. Signal output typically 1.5 μA / (1000 μmol m-2 s-1)
0.01 %/K
± 5 %
0 °C … + 40 °C
55 cm
BNC
Not required
Height: 5.5 mm
Length: 76 mm
Width: 26 mm
Diffuser diameter: 0.2 mm
Measurement of photosynthetic photon fluence rate in air or water
E.g. ULM-500
BNC
Typically -3.5 μA / (1000 μmol m-2 s-1) in air
Diameter: 1 cm
Length: 11 cm
62 g
WinControl-3 Software
General Features and Graphical User Interface
WinControl-3 represents the latest version of the WinControl software family. Presently, WinControl-3 operates the Universal Light Meter ULM-500 and JUNIOR-PAM fluorometers as well as the MONITORING-PAM system, MINI-PAM-II and MICRO-PAM heads.
If the ULM-500 is controlled by this software, the computer can be used as continuing data acquisition unit powering the ULM-500, so that its internal batteries will not be used up.
WinControl-3 is capable of long-term data acquisition (up to several months) allowing the user to define different sampling frequencies. Experimental protocols can be performed automatically with programmable batch-files.
The WinControl-3 software can also be used to enter calibration factors and sensor names in the ULM-500. In addition, the predefined application settings for the field use can be changed conveniently.
Usage
Highlights
- Data logger with high data storage capacity
- Multiple sensor can be read in parallel
- PAR calibration for PAM devices
- Low power consumption, long battery life
Downloads
- Software: WinControl-3.40_Software.exe
- Manuals & Documentation: ULM-500 Manual
- Product Information: Flyer ULM-500