Questions tagged [calibration]

Correlate the readings of an instrument, sensor, etc. with those of a standard in order to check its accuracy. Adjust experimental results to take external factors into account or to allow comparison with other data.

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Is AC current clamp meter accuracy affected by the inner wire curving around the outside?

I have a SCT013-030 current clamp sensor I plan to use to read out the power usage of a mains AC load. It works by wrapping around one of the AC strands of wire to measure the magnetic field. The one ...
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Two DPS310 sensors coded same but different values. Why?

I have two DPS310 sensors. My aim is to find the altitude value from these sensors. Both sensors give different altitude values. I have checked the calibration coefficients. Two are similar, but have ...
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How do I calculate accuracy marked as ±(4 ppm rdg + 10Digit)?

Trying to figure out the correct way to calculate accuracy with LSD. I looked at a few sources, but I'm still confused on the topic. The question: A digital voltmeter can display counts up to 1999999 ...
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1 vote
2 answers
86 views

Can calibration break PSUs?

I was tasked with rounding up all of my company's measurement devices (calipers, power supplies, scales, etc.) and arranging a visit from a calibration services company. The company came and ...
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VNA Port Extension method

I have a PCB that has been handed to me that needs a match network setting between an SMA antenna and a Bluetooth module so operating freq = 2.4GHZ. I have a PICO 106 VNA and I have calibrated the ...
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3 answers
78 views

How does accelerometer calibration work?

Inside a MEMS accelerometer there are some miniature spring-mass structures that displace under gravity or external force (acceleration). These forces are proportional to or can be indirectly ...
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2 votes
1 answer
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Does NTC temperature measurement need calibration?

I'm creating some temperature sensors for home use. To measure outside and rooms' temperatures. Range from -30 °C to +50 °C. Temperature measurement is based on 10k NTCs SDNT2012X103F3950FTF (B=3950K, ...
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1 vote
2 answers
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MAX6675 k-type thermocouple ADC is giving high readings

I have designed and built a small fairly simple circuit that uses a MAX6675 chip to take temperature readings from a multiplexed array of 16 k-type thermocouples. Datasheets: MAX6675: https://www....
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Calibrating 500 kg load cell with ESP32 and HX711 without putting actual 500 kg on it! 3 V excitation

I am making a 500 kg scale using ESP32 and HX711. It is battery powered and using 3 V excitation. In calibration process , I increase the weight by 50 kg steps and read the HX711 output and then use ...
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1 answer
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When and why does embedded Electronic Control Unit (ECU) use default calibration values? [closed]

Typical embedded ECU stores real calibration values and default calibration values in Non-Volatile Memory (NVM). Let's say ECU is Steering Controller and its primary function is Lane Keep Assist (LKA)....
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Did I calculate my force sensor resolution correctly?

I am trying to calculate the resolution of my simple force sensor system in Newton [N]. The sensor system consists of a simple voltage divider, where the voltage across the FSR is measured by an 8-bit ...
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How do I find the accuracy / uncertainty of my force sensor system?

I have built a force sensor using an arduino and a self built force sensitive resistor (FSR.) The sensor system consists of a simple voltage divider, where the voltage across the FSR is measured by an ...
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How to VNA-calibrate a soldered coax with a 0201 50 ohm load at 2.4 GHz?

I need to tune a tiny ceramic antenna for Bluetooth Low Energy and I'm somewhat new to these high frequencies... I soldered a 0.81 mm diameter coax right before the Pi-network pads and want to ...
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What methods are there to calibrate force sensors?

I have a DIY force sensor made from velostat in a voltage divider - Arduino configuration outputing voltage to a display from an applied force to the sensor. I'm looking for sources / books / pdfs / ...
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2 answers
42 views

Does shunt calibration of a sensor also correct for zero error?

In the datasheet for a load cell (shown below), it says that shunt calibration data is given, also they have mentioned the zero balance. Does the shunt calibration consider zero balance? Meaning, do I ...
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STM32F7xx ADC compensation of offset error

I'm using STM32F765VI in my project and I've some troubles with proper compensation of ADC offset error. This STM has (probably) no ADC self-calibration: the bit CAL in ADC_CR2 register does not exist,...
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Charaterization of waveguide to coaxial adapter

I'm trying a method to characterize a high frequency waveguide to coaxial adapter( 2-port network). For this, I use 3 adapters A1, A2, A3. After a TRM calibration, I measure A1 connected with A2 with ...
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1 answer
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Why are IMU sensors calibrated in the ways that they are?

I'm using a BNO055 IMU for a project, and I'm learning to calibrate each sensor separately. The gyroscope is calibrated by standing the device still in any position The magnetometer is calibrated ...
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Old Fluke 23 service manual?

I'm looking for my old Fluke 23 service or calibration manual but all the Fluke 23 I find in a google search are the series II or series III. Mine is the oldest I guess, it has no series. Thanks. ...
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1 answer
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Device RF input calibration setup

A device requires RF input calibration. The input signal specification is: CW, 60MHz, 0.0 dBm. The user manual recommends setup 1 (fig below). Provided that the Signal Generator is capable of ...
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2 votes
3 answers
978 views

Fine-tuning/calibrating DS18b20 thermometer via 1-wire

I am trying to enable remote reading of the temperature gauges in my furnace room by adding DS18B20 thermometers. Since I had some Raspberry Pis and DS18B20s, and ...
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Centering joystick potentiometers in a controller

I've replaced a joystick in my Dual Shock 4 controller, because it was getting stuck. The readings of the new joystick are offset to right and down. I've read that you can recenter the readings by ...
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1 vote
2 answers
168 views

MPU9250 Gyro Calibration-Offset

I'm working with mpu9250 gyroscope and I got fine measurements for beginning period (few minutes). I calculated offset at start in manner to average sum of first 1000 results from mpu9250 gyro. But If ...
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2 votes
0 answers
174 views

Calibrating RTL-SDR Power with 50 Ohm Load and Thermal/LNA Noise

Ultimately I'm generating some spectrum plots in L-Band (1200-1800 MHz) and I need to get calibrated flux units (dBm/Hz) for my y-axis. I need a little assistance on creating this memo. I've been ...
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Is my magnetometer calibrated correctly?

I am calibrating the AK8963 on the MPU9250. The first plot shows original mag readings and the last plot shows readings corrected for soft and hard bias. I am following the guidance of Kris Winer: ...
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2 answers
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How to change get positive value on my weighting Scale?

My weighting Scale is working fine when I keep weight after the start. But I am getting stuck when I keep weight before starting my weighing device. When I do this auto-calibrate with available weight....
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2 votes
0 answers
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Tektronix P6015 Replacement Potentiometer Considerations

I’ve acquired (saved from the landfill) an old Tektronix high voltage probe, model P6015. The probe body and cable are in decent condition, but I discovered two damaged potentiometers in the ...
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3 answers
202 views

STM32 runtime Variable value manipulation

So basically I am not an expert, altho I think I have a good basis of knowledge. I am using an STM32 Cortex 4 (discovery) for a hobby CNC machining application. So lets assume we have a SW under ...
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2 votes
1 answer
157 views

How to calculate measurement error in an exponentially non-linear sensor? (self made pressure sensor)

I'm trying to calculate the measurement error from a home-made pressure sensor which I have in a voltage divider circuit. It has the same negative exponential non-linear resistance characteristics as ...
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24 votes
7 answers
5k views

How do we know that voltmeters are accurate?

Something that has always puzzled me is how we know the accuracy of voltmeters. From googling around, it seems that today's digital voltmeters use an ADC. An ADC works by comparing the voltage that is ...
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1 vote
1 answer
154 views

Dual slope ADC circuit

I`m currently building a dual slope ADC with discrete components. As expected, some errors were observed. I have calculated both the gain error and offset error variables. Now that I know these ...
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-2 votes
1 answer
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Calibration of response of electronics : LTSpice [closed]

I would like to calibrate my electronics. Row signal is something like pulse-A, width is 40nsec. When I input this signal to preamplifier, output is something like pulse-B. I would like to calibrate ...
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1 vote
0 answers
55 views

EMC-BCI. Coil injection and probe were calibrated at 100 ohm

As the title says my coil injection and coil probe were calibrated into 100 ohm loop line Impedance and it resulted an insertion loss (dB) for the coil injection. and transfer impedance (dBΩ) coil ...
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1 vote
0 answers
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How to Design method to Program & Calibrate a Panel of PCBs

I'm designing a sensor-package PCB which needs to be programmed and calibrated while still in a panel of 10. I'd like to avoid a large bed-of-nails type setup for this step so that the panel can ...
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1 vote
0 answers
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Calibrating a k type themperature probe for a PID controller

I just purchased an inkbird PID controller with a k probe to controll a temperature in an oven. I calibrated the k probe at 60F using a trusted digital thermometer with 2 probes. I installed the probe ...
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2 votes
2 answers
191 views

Unexpected YAW angle from magnetometer

I have some doubts about a magnetometer application. I am trying to get YAW angle value from magnetometer data and so I am doing the following: ...
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1 vote
2 answers
544 views

What device can I use as a load to calibrate a power meter accurately?

In old times calibrating a power meter was as easy as connecting 1x, 2x, 3x high power halogen bulbs to get realistic data, free of reactive power or strange waveforms with strong harmonics. Nowadays ...
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1 vote
1 answer
51 views

Sensor input calibration for wider range

I get minimum voltage output from my sensor as 2.2V and max voltage as 2.65V. I want to change this voltage to 0-5V range so that the controller ADC can calibrate input in a wider range. How can I do ...
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0 votes
2 answers
126 views

Linearizing a load cell

As I understand it most load cells (all?) are only approximately linear. To improve the linearity would a 3 point calibration be sufficient? For example, at no load, half load and maximum load. If so, ...
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12 votes
1 answer
1k views

What makes OSL (Open Short Load) calibrators so expensive/sophisticated?

An OSL that can go up to the GHZ can costs several hundreds if not thousands of dollars, what makes them so special? My theory is that a load involves some sort of special resistor and mantaining a ...
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0 answers
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Correction factor for monitor based off orthogonal regression

I'm seeking some clarity about providing a correction factor for an instrument based off orthogonal regression. Currently I have a machine I built myself, co-located with a reference monitor recording ...
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1 vote
2 answers
359 views

CNC feedback mechanism

The GRBL library for Arduino looks very comprehensive but I like to understand how things work before I try to build them. Something I don't understand is how these systems get positional feedback. I ...
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2 votes
2 answers
1k views

How to debug new Brushless DC motor not working? [closed]

I'm building an autonomous boat, for which I so far used this brushless motor powered by this drone ESC (both pictured above). I now want to start using a more efficient motor, so I bought the 12V ...
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0 votes
3 answers
570 views

how to calibrate my multimeter temperature probe

I have a multimeter with the following temperature accuracy for its Type K probe ±3% of reading ±5C The display is in steps of 1C I attempted some calibration: In ...
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0 votes
1 answer
252 views

Calibrate/adjust sensitivity of a 801S Vibration Sensor Module

I have some 801S Vibration Sensor Module I want to use for a project, but I need to make sure they have the same sensitivity. The sensor module has a potentiometer which makes it possible to adjust ...
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1 answer
44 views

Calbration of an infrared sensor

I found on a site that it is important to know the temperature of the infrared sensor while calibrating the infra red sensor, but I could not find the real reason behind this. Anyone knows it?
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1 answer
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How to calibrate any magnetometer when sensor is changing the location?

I found magnetometer calibration is done for soft/hard distortions also for tilt compensation using gyro data as well, but all of them perform for know step of the procedure (rotating aligned with ...
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0 votes
1 answer
148 views

What should I use as a test load to calibrate a UPS?

I have a 1440VA (980W) Uninterruptable Power Supply (UPS) which I bought a while back to protect my computers from power fluctuations and possible outages. Recently the battery failed and so I ...
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1 vote
1 answer
392 views

Soldered wire or test connector for VNA measurement?

I am designing a PCB for a IoT device, which will have an antenna inside a space-constrained plastic enclosure with metal screws. I know that I will have to tune the frequency response of the antenna ...
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2 votes
1 answer
62 views

Offset Error Changing after Calibration of Output

I have a circuit (shown in figure 1) that is supposed to function as a precision analog output. It outputs a DC voltage in the range of either ±10V or ±5V, depending on which gain resistors are used. ...
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