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2answers
53 views

How to Generate a Calibration Signal?

I'd like to generate an integrated calibration signal for a biopotential amplifier. I'd like to generate a 0.5mV square wave (within 5%) at 200Hz (give or take on the frequency). I'm thinking of ...
0
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1answer
41 views

Load Cell Data Problem - INA125P + Arduino Uno

I am currently reading data from my 30kg load cell with my Arduino UNO board and passing this data to my PC. I am using INA125P to amplify the voltage of my load cell and it is established on a bread ...
1
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1answer
137 views

Legal requirement for measurement equipment calibration in manufacturing

We have a build approaching but one of our PSU's used in the function tester will be out of calibration in 3 weeks. Most likely we will complete the build whilst the PSU is still within it's ...
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2answers
44 views

VCTCXO control voltage circuit recommendations?

I'm building a frequency calibration rig. Right now, I've got a fixed TCXO and it has an uncalibrated drift versus GPS of around 0.185 ppm ±50 ppb. I'm prepared to simply subtract 0.2 ppm from the ...
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1answer
54 views

Characterizing a capacitive touchscreen

Is it possible to measure a meaningful impulse response of a capacitive touchscreen such as the one you might find on a mobile device, with the goal of "calibrating" devices with different ...
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1answer
78 views

black level calibration in image sensor

For one camera, the black level of the sensor will make the output non-zero when it is covered. For example the output of the sensor is 10bit and black level is 63, if the output is reduced by black ...
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1answer
48 views

Analogue oscilloscope probe selection

Recently, I have bought an oscilloscope with model Panasonic VP-5512A Panasonic VP-5512A 100 MHz 2CH+1/2+1/2 Dual Timebase It is an analog oscilloscope. ...
0
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1answer
78 views

How is an accelerometer initially calibrated?

Referring to a MEMS accelerometer, how is the laboratory, initial calibration being carried out? Is the gravitational acceleration involved as a reference, or is the actual analog data being ...
0
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1answer
147 views

how to calibrate ADXL345 accelerometer?

I have ADXL345 digital accelerometer by Analog Devices. I use Beaglebone ADXL345 library that exist here: http://inspire.logicsupply.com/2014/08/beaglebone-3-axis-accelerometer.html So I can read the ...
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2answers
91 views

How can you auto-calibrate a conductance sensor?

Sensors need to be calibrated every so often, so that the voltage/current change due to the change in the conductance is always the same, and the signal conditioning of that voltage/current is always ...
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0answers
67 views

What is the frequency of IR2155 in this circuit?

What is the frequency of IR2155 in this circuit? I made calculations: f = 1/(1.4*(180kΩ+150Ω)*0.0047uF) = 1/(1.4*180150Ω*4.7*10^-9 F) = 844Hz Please tell me if my calculations are done correctly? ...
0
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1answer
103 views

Temperature calibration for MCP9808 [closed]

Reading a lot, I have found nothing about calibration for the MCP9808. I have read the datasheet and understand that the chip converts the temperature to Celsius. The given accuracy in the datsheet is ...
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1answer
1k views

How does a smart phone measure the battery power?

A smartphone (assume Android) usually displays the battery percentage from 0 to 100%. I am assuming this is the usable power capacity of the battery. I have several questions: 1) How exactly does it ...
0
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1answer
100 views

Calibrating buck LED driver by altering Vsens

Many switch mode buck LED drivers use a current mode scheme with a sense resistor back to a Vsens or Current Sense input on the chip. A good example is the LM3404. Here's the typical use circuit: I ...
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0answers
39 views

How to calibrate pico-ammeter votage bias?

I'm using Keithley 6487 pico-ammeter. It's strange when I turn on the machine without connecting any circuit, there exists 0.05 Volts difference between the in and out probe. So I have to add -0.05 ...
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1answer
64 views

LabVIEW Calibration Routine

I have a hardware setup where I am trying to null the input offset voltage of an op-amp using an I2C digital potentiometer. The op-amp inputs are shorted and I am measuring the output using an NI Data ...
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0answers
119 views

Li-ion battery calibration technique

As you know the li-ion batteries have flat voltage curve and it is not possible to detect battery state of charge (SOC) from voltage accurately. We use fual-guage which measures the accumulated ...
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2answers
190 views

Using a trimmer pot to output a percentage of voltage

I am trying to do a project where I am getting two (or more) voltages and averaging them all out. Then I would like to use a trimmer pot to adjust the voltage by a percentage, basically as a ...
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3answers
98 views

Calibrating the output voltage

I have a device which has a 16 bit D/A converter which through an analog linear circuit generates an output voltage between -1V and 1V. I have 32 of such channels on my device. simulate this ...
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0answers
488 views

How to calibrate a Kill A Watt meter and understand its hidden service menu [closed]

I found a hidden menu within the Kill A Watt P4400 meter, which is accessed by holding down the Volt and Hz buttons. Although I rendered my meter unable to measure accurately because of my futzing ...
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2answers
166 views

Calibration and trapping the CPU

The following code is meant for MSP430. Can somebody help me what is the purpose of trapping the CPU? How will the program proceed if the CPU is trapped there? ...
3
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2answers
1k views

Temperature compensation of LSM303DLHC accelerometer / magnetometer

ST Microelectronics makes the LSM303XXXX, a popular range of 3-axis accelerometer / magnetometer sensors that are used on Arduino breakout boards, etc. The older LSM303DLH sensor has been replaced ...
4
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1answer
275 views

How to calibrate an optical particle sensor (Mie scattering)

I have a very simple sensor that basically emits infrared light (1 micron wavelength in the infrared range). The light scatters off particles whose diameter is of the same order of magnitude as the ...
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2answers
505 views

Where can I send my 0.005% 1 PPM tempco calibration resistors to find out their “true” value?

edit: putting this at the top because people keep answering questions I didn't ask: Where can I get this done cheaply by a place that is hobbyist friendly? I don't even know where to look. I imagine ...
1
vote
1answer
434 views

PIC18F26K80 ADC calibration using Bandgap

The PIC18F26K80 errata sheet mentions that the ADC has an offset error as high as 25 bits and discusses one workaround copied from the errata here: A/D Offset The A/D may have high offset error, up ...
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3answers
247 views

Does calibration involve fixing electronics or mechanical part?

My question is not 100% related to electronics design but it might be because I don't know the answer. I'm writing a simple research on anemometer calibration. The thing is all the resources I found ...
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1answer
114 views

Torque measurement device calibration

I don't know if I'm at the right place to ask this question but here is my trouble : I'm trying to find a good way of calibrating a electronic device used to measure small torques (0 -> 25 mNm). ...
4
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2answers
4k views

How to calculate a correction factor for two sensors

Suppose one has two sensors placed in the same environment (thus should be reading the same environmental data). But not being perfect instruments, there is a discrepancy between the two sets of ...
6
votes
2answers
594 views

How often should I have to set oscilloscope probe's capacitance?

I got a new Owon SDS7102 oscilloscope and I'm using the included oscilloscope probes with it. The manual says that the proper calibration procedure is to let the oscilloscope work at constant ...
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3answers
3k views

How do you Calibrate 32.768kHz crystal for PIC24 RTCC

I'm trying to figure out the best method for PIC24 RTCC crystal calibration. Their application note states two methods: using a lookup table and using a reference system clock. According to them the ...
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2answers
175 views

Calibration of reading of current measuring cicuit

Ok ,I'm making a small current meter device I was able to take the voltage coming from a "shunt resistance " which is a current transducer that gives me an specific analog signal that proportional to ...
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1answer
3k views

Magnetometer ∞ shaped calibration

In mobile phones and other devices using a 3-axis electronic compass, a ∞/8/S shaped movement is used to calibrate the magnetometer as shown in these videos. Why is this movement performed, what is ...
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2answers
4k views

Magnetometer dynamic calibration

I am working on a Magnetometer AK8975 being a part of an IMU. Which seems to be very tricky for me. This chip gives a 3D vector as output describing earth's magnetic field at any place on earth or ...
2
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2answers
2k views

Confusing oscilloscope calibration signal

EDIT: See last paragraph I recently got a cheap 2-channel oscilloscope (Hitachi V-212). Judging from the "calibration not required" sticker on the front, it's been beaten up and/or neglegted (by the ...
4
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2answers
987 views

Network Analyzer HP 8752A Calibration

How can I do a two-port response calibration to measure S-parameters (Reflection and Transmission) for an HP 8752A Network Analyzer? The DUT (two coils, one in air and one in salt-water) is ...
2
votes
1answer
172 views

Precision calibration tools

What "affordable" voltage and current calibrations tools are available? I'm specifically looking for Voltage (and preferably current) metering 0.05% Accuracy minimum (preferably 0.01%) 14 bit+ ...
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4answers
9k views

How to calibrate a temperature sensor

I am using an LM35 temperature sensor, which produces an output of 10.0 mV/°C. My circuit will handle temperatures up to around 90C What can I do to check the LM35 output, and maybe fine tune it for ...
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3answers
725 views

What Ways to Calibrate a Multimeter?

How can one calibrate a multimeter, like a UT61E or any other multimeter in the 50 ~200 $ pricemark, when one does NOT have an expensive FLUKE nor a friend who has a FLUKE)
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3answers
882 views

How viable is it to just use 1% resistors and calibrate out the error?

At the moment, I use 0.1% resistors to get accurate voltage measurement through a voltage divider. However, the cost is high, so I was thinking of using 0.5% or 1% resistors and calibrating out the ...
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2answers
2k views

How to calibrate multimeters?

Without buying an expensive calibration tool, how can I accurately calibrate my multimeters?