November 1, 2017 at 19:46Budget Spectrometer Pulsemeter Uprtek MF250N
A spectrometer is a device that measures the spectrum of light and allows you to determine parameters such as color temperature and color rendering index . Pulse meter - a device that measures the pulsation of light.
The Uprtek MF250N combines these two instruments and, apparently, is the cheapest spectrometer in the world.
There are two types of spectrometers - those that analyze light and those that analyze the properties of materials in reflected light. The wikipedia article is about the second, and the spectrometers that I talk about are used to analyze light.
Such spectrometers are quite expensive (primarily due to the fact that they are produced in small batches). UPRtek MK350D ( my review), which I use in the Lamptest project, costs $ 1700 and it is still considered cheap. Budget spectrometer-pulsmeter Uprtek MF250N costs half the price - $ 850. It differs from more expensive models by slightly lower accuracy, the lack of the ability to connect to a computer and battery power. Until the latest firmware, data could only be viewed on the device’s screen, but the new firmware added the ability to save data to a memory card that was previously used only for updating firmware.
Uprtek spectrometers are manufactured by the Taiwanese company of the same name . The St. Petersburg company INTECH Engineering participated in the development of spectrometers and the writing of mathematical models., she also sells Uprtek products in Russia. Once again I want to express my gratitude to this company and its CEO Aleksey Pankrashkin for the MK350D spectrometer provided for the Lamptest project .
UPRtek MF250N analyzes visible light in the wavelength range of 380-780 nm and can perceive light with illumination of 70-70000 lux. The resolution of the matrix is 16 bits, the step of measuring a wavelength of 1 nm, the step of writing to a file is 2 nm, the accuracy of measuring the wavelength is ± 1 nm, the error in measuring illumination is ± 5%. The peak wavelength, correlated color temperature (measurement error ± 3.5%), and the average color rendering index Ra (measurement error ± 2.5%) are calculated from the spectrum. The accuracy of measuring color parameters of the MF250N is slightly lower than that of the more expensive Uprtek spectrometers (for them, the error in measuring color temperature does not exceed 2%, and the error in measuring CRI is 1.5%).
Using a separate sensor, the parameters of light pulsation are measured. Measurement speed - 5 measurements per second. The range of illumination for measuring ripple is 30-60000 lux. The measured pulsation frequency is 5-2000 Hz. Displayed ripple parameters: ripple index, ripple coefficient, level of visible strobe effect (SVM), ripple frequency. There are FFT (Fast Fourier Transform) and Oscilloscope modes.
Power - 4 AA batteries. Battery life up to 5 hours. The size and weight of the device with batteries is 80x65x30 mm, 300 g.
A cover is included in the package.
The measuring head of the spectrometer is disconnected so that it can be turned over. A USB Type C connector is used, but the pin assignment is most likely non-standard.
The sensor window is closed with an opaque cover. In the center is the white window of the spectrometer sensor (the light is decomposed onto the spectrum using a diffraction grating and enters the linear CMOS matrix), and the ripple sensor window is on top.
The device is powered by four AA batteries. You can use batteries.
On the left side is an on / off button.
On the right side is a button to start spectrum measurement.
The instrument screen measures 43 x 58 mm (2.8 "). It is not touch-sensitive. The modes are selected using four buttons.
On the right side there is a rubber sticker, under which there is a MiniUSB connector and a microSD card slot. The connector cannot be used, and the measurement results can be saved to the card.
When you turn on the device offers to calibrate. For calibration, close the sensor cover and press the circle button.
Management is carried out through the menu. The arrow buttons move the pointer around the menu, the dot button activates the desired item, the back button allows you to return to the main menu.
The first item is the basic parameters of light.
CCT - color temperature;
CRI - color rendering index;
Lux - illumination;
λP is the peak wavelength;
iTime - integration time (the spectrometer takes many measurements during the specified time and calculates the average values. The less light, the longer the integration time is required).
The second point is the spectrum.
The third, fourth and fifth paragraphs concern the measurement of ripple. Ripple is measured continuously. You can stop and continue continuous measurement (HOLD mode) with the button on the right side of the device.
The main ripple measurement screen is FLICKER mode.
Findex - ripple index. A parameter that takes into account both the change in brightness during pulsation and the duty cycle of pulses.
Fpercent (%) - percentage ripple. When there is no ripple, it is zero. At maximum ripple, its value is 100%. The ripple percentage is calculated from the minimum and maximum light brightness.
SVM (Stroboscopic Visibility Measure) - the level of visible stroboscopic effect.
Freq (Hz) is the main ripple frequency.
The FFT mode displays the frequency distribution of the ripple using the fast Fourier transform method.
LIGHTWAVE mode displays the waveform of the ripple shape.
In SYSTEM mode, you can enable or disable the sound of pressing buttons, adjust the screen brightness and power saving mode, see the firmware version.
Measurement data can be saved to the memory card in BASIC and FLICKER modes. To do this, press and hold the button with a dot, being in one of these modes.
Each new save is assigned a new number.
Data is saved in Excel format. Spectrometry results in the RAW_SPD.XLS file, ripple measurements in the RAW_FLK.XLS file.
Each line in the RAW_SPD.XLS file is a new dimension. In column 1 - measurement number, in columns 2-6 color temperature, color rendering index, illumination, peak wavelength, integration time. In columns 7-207, the values of the level according to wavelengths (the unit is the value of the level at the peak wavelength).
The file format is RAW_FLK.XLS.
It is not convenient that the device cannot simultaneously measure the spectrum and ripple parameters. The transition from one mode to another is also not the most convenient - to switch from the spectrum parameter measurement mode to the ripple measurement mode, you need to press four buttons: (back, right, right, point).
It’s not very convenient that there is no automatic saving to the memory card and every time you need to hold the button with a dot for two seconds. On the other hand, it’s good that the ability to save appeared at all, because in previous versions of the firmware it was not.
However, do not forget that the Uprtek MF250N is half the price of other spectrometers and it also measures the ripple, so that it can be forgiven for minor flaws, given that its measurement accuracy is only slightly less than that of much more expensive instruments.
© 2017, Alexey Nadezhin
The Uprtek MF250N combines these two instruments and, apparently, is the cheapest spectrometer in the world.
There are two types of spectrometers - those that analyze light and those that analyze the properties of materials in reflected light. The wikipedia article is about the second, and the spectrometers that I talk about are used to analyze light.
Such spectrometers are quite expensive (primarily due to the fact that they are produced in small batches). UPRtek MK350D ( my review), which I use in the Lamptest project, costs $ 1700 and it is still considered cheap. Budget spectrometer-pulsmeter Uprtek MF250N costs half the price - $ 850. It differs from more expensive models by slightly lower accuracy, the lack of the ability to connect to a computer and battery power. Until the latest firmware, data could only be viewed on the device’s screen, but the new firmware added the ability to save data to a memory card that was previously used only for updating firmware.
Uprtek spectrometers are manufactured by the Taiwanese company of the same name . The St. Petersburg company INTECH Engineering participated in the development of spectrometers and the writing of mathematical models., she also sells Uprtek products in Russia. Once again I want to express my gratitude to this company and its CEO Aleksey Pankrashkin for the MK350D spectrometer provided for the Lamptest project .
UPRtek MF250N analyzes visible light in the wavelength range of 380-780 nm and can perceive light with illumination of 70-70000 lux. The resolution of the matrix is 16 bits, the step of measuring a wavelength of 1 nm, the step of writing to a file is 2 nm, the accuracy of measuring the wavelength is ± 1 nm, the error in measuring illumination is ± 5%. The peak wavelength, correlated color temperature (measurement error ± 3.5%), and the average color rendering index Ra (measurement error ± 2.5%) are calculated from the spectrum. The accuracy of measuring color parameters of the MF250N is slightly lower than that of the more expensive Uprtek spectrometers (for them, the error in measuring color temperature does not exceed 2%, and the error in measuring CRI is 1.5%).
Using a separate sensor, the parameters of light pulsation are measured. Measurement speed - 5 measurements per second. The range of illumination for measuring ripple is 30-60000 lux. The measured pulsation frequency is 5-2000 Hz. Displayed ripple parameters: ripple index, ripple coefficient, level of visible strobe effect (SVM), ripple frequency. There are FFT (Fast Fourier Transform) and Oscilloscope modes.
Power - 4 AA batteries. Battery life up to 5 hours. The size and weight of the device with batteries is 80x65x30 mm, 300 g.
A cover is included in the package.
The measuring head of the spectrometer is disconnected so that it can be turned over. A USB Type C connector is used, but the pin assignment is most likely non-standard.
The sensor window is closed with an opaque cover. In the center is the white window of the spectrometer sensor (the light is decomposed onto the spectrum using a diffraction grating and enters the linear CMOS matrix), and the ripple sensor window is on top.
The device is powered by four AA batteries. You can use batteries.
On the left side is an on / off button.
On the right side is a button to start spectrum measurement.
The instrument screen measures 43 x 58 mm (2.8 "). It is not touch-sensitive. The modes are selected using four buttons.
On the right side there is a rubber sticker, under which there is a MiniUSB connector and a microSD card slot. The connector cannot be used, and the measurement results can be saved to the card.
When you turn on the device offers to calibrate. For calibration, close the sensor cover and press the circle button.
Management is carried out through the menu. The arrow buttons move the pointer around the menu, the dot button activates the desired item, the back button allows you to return to the main menu.
The first item is the basic parameters of light.
CCT - color temperature;
CRI - color rendering index;
Lux - illumination;
λP is the peak wavelength;
iTime - integration time (the spectrometer takes many measurements during the specified time and calculates the average values. The less light, the longer the integration time is required).
The second point is the spectrum.
The third, fourth and fifth paragraphs concern the measurement of ripple. Ripple is measured continuously. You can stop and continue continuous measurement (HOLD mode) with the button on the right side of the device.
The main ripple measurement screen is FLICKER mode.
Findex - ripple index. A parameter that takes into account both the change in brightness during pulsation and the duty cycle of pulses.
Fpercent (%) - percentage ripple. When there is no ripple, it is zero. At maximum ripple, its value is 100%. The ripple percentage is calculated from the minimum and maximum light brightness.
SVM (Stroboscopic Visibility Measure) - the level of visible stroboscopic effect.
Freq (Hz) is the main ripple frequency.
The FFT mode displays the frequency distribution of the ripple using the fast Fourier transform method.
LIGHTWAVE mode displays the waveform of the ripple shape.
In SYSTEM mode, you can enable or disable the sound of pressing buttons, adjust the screen brightness and power saving mode, see the firmware version.
Measurement data can be saved to the memory card in BASIC and FLICKER modes. To do this, press and hold the button with a dot, being in one of these modes.
Each new save is assigned a new number.
Data is saved in Excel format. Spectrometry results in the RAW_SPD.XLS file, ripple measurements in the RAW_FLK.XLS file.
Each line in the RAW_SPD.XLS file is a new dimension. In column 1 - measurement number, in columns 2-6 color temperature, color rendering index, illumination, peak wavelength, integration time. In columns 7-207, the values of the level according to wavelengths (the unit is the value of the level at the peak wavelength).
The file format is RAW_FLK.XLS.
It is not convenient that the device cannot simultaneously measure the spectrum and ripple parameters. The transition from one mode to another is also not the most convenient - to switch from the spectrum parameter measurement mode to the ripple measurement mode, you need to press four buttons: (back, right, right, point).
It’s not very convenient that there is no automatic saving to the memory card and every time you need to hold the button with a dot for two seconds. On the other hand, it’s good that the ability to save appeared at all, because in previous versions of the firmware it was not.
However, do not forget that the Uprtek MF250N is half the price of other spectrometers and it also measures the ripple, so that it can be forgiven for minor flaws, given that its measurement accuracy is only slightly less than that of much more expensive instruments.
© 2017, Alexey Nadezhin
