Measurement is the assignment of numbers to objects or events. All measurements consist of three parts: magnitude, dimensions (units) and uncertainty.

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42 views

Measure Power Supply Noise Rejection at MHz and GHz

I'm trying to characterize the performance of a power supply module, one of the criteria being power supply noise rejection, in particular at different frequencies. For testing 10Hz to 100kHz, I was ...
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0answers
35 views

Wirelessly distance measurement? [closed]

I am trying to measure an object less than 30 meters away with relatively high accuracy. the environment may be somewhat un-predictable (outdoor, obstacle etc), what are some of the best options out ...
0
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1answer
24 views

What is the difference of a loadell input and output resistance?

I am trying to understand the specifications of a load cell and there are the input and output resistance as you can see here, it says 1090±10Ω for input resistance and 1000±10Ω of output resistance. ...
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1answer
50 views

Does this loadcell's creep mean that I can not let a constant load on the loadcell?

I want to build a connected scale that I can set coffee powder (for example) on it and check over the internet how much of coffee I still have without going to see it. Usually all loadcells have a ...
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1answer
48 views

Cheap sensor for measureing air dissolved in water?

I have been experimenting a bit with hydroponics lately, and one of the important things when building a hydroponic system is to aerate the water/nutrient solution. This is usually performed with an ...
5
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2answers
194 views

Why to use Siemens to measure high resistance?

I have a Fluke 87V and I can see lots of EEVBlog videos were Dave measure high resistance values, and instead of using the Ohms range, he goes to the Siemens range (nS actually). My question than ...
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1answer
89 views

How to measure ESR

I have a bunch of capacitors but no clue of what ESR they have. Is there a way to measure the ESR? Can I set up a test circuit to measure it?
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2answers
80 views

Measurements with multimeter giving paradoxical values

I study civil engineering (majoring in electrical engineering) and part of the program in my university is a design project. For this project my team developed a PCB and naturally it was full of bugs. ...
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1answer
36 views

Measure/Access Information from small device through audio jack (mic)? [closed]

I've got a small device that I have not yet opened. It sends some unknown sequence of voltage and current through a medium for a few seconds thereby calulating and then displaying a result value on a ...
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1answer
89 views

What is the difference between Pack- and Bat- on a LiPo Battery

I am trying to figure out how to use the TI bq34z100 to measure the charge in a 29.6v 8s1p 5.4Ah pack. Out of this pack I have A charge connector with + and - and a discharge connector with + and - ...
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0answers
41 views

How to measure force on line

Trying to figure out how to measure force on a string which is being pulled. I can't attach it to anything and the force is great enough to cause it to unravel from a spool. Was thinking of ...
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2answers
82 views

ADC & sensor calibration

I have a scenario that implies measuring 2 inputs: - voltage through a resistive divider - current through a hall sensor followed by opamp for offset, direction and scaling In my software, each ...
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1answer
47 views

Bipolar Transistor PTAT Cell and setup

I am in a measurement systems class at school, and we have a project to design a measurement system. I was reading my text book when a diagram caught my fancy, and I thought I would try to build it. ...
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1answer
74 views

Significant figures on component's values

I'm reading a book where resistor values are discussed: I did not understand about how 3 significant figures can cover uncertainties from 1 to 0.1 % as stated in the 1st paragraph 6th line of the ...
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votes
2answers
100 views

How can I multiplex my oscilloscope probes?

Let's say that I'm tasked with the job of measuring the propagation delay of each inverter in a 7404 hex inverter. I've got a pulse generator, a power supply, and an oscilloscope with two probes, so ...
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votes
2answers
261 views

Measuring average current with uC and current shunt

This is my first post. I'm a software guy trying to do hardware so be gentle :) Circuit I'm designing a small circuit (see pic, and sorry for messy schematic) that plain and simply is a bunch of ...
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0answers
107 views

Measuring radon levels

I saw a commercial full built sensor/alarm which can measure it but I cannot find any IC with that function. What is the type of component to use to measure radon level in the air?
2
votes
1answer
152 views

How to measure weight?

Last few months I am working on personal project -- I want to measure weight of beehive during the year and then save the results. Beehives has usually from 100 to 200 kg and during one day, the ...
0
votes
1answer
47 views

Interfacing with the MLX91206

I am planning on using an MLX91206 to measure the current draw of a set of Peltier elements. They draw up to 17.3A at 24V. However I would like to measure their current draw without interfering by ...
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1answer
52 views

Thermocouple on a grounded stainless steel box

My present project is a ~6kW switching converter in a sealed stainless steel box. The box is grounded well. When I put a thermocouple on the surface of the box, the reading is noisy. Even if I put ...
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2answers
144 views

Wheastone Bridge vs. voltage divider [closed]

I read that Wheatstone bridge is more sensitive than voltage divider, since it acts as a DC offset removal circuit. But I can't understand why ?
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0answers
32 views

MPX2100DP only measures depression

I'm trying to read out the analog differential pressure sensor MPX2100DP. In my first approach I used an oscilloscope to visualize the change of voltage. My basic setup was only the sensor connected ...
3
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2answers
168 views

Ceramic capacitor value changes after soldering!

I am debugging a power amplifier circuit and trying several capacitors values to fine tune the design to meet the frequency response specifications. All the 0603 and 0805 ceramic capacitors are ...
0
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2answers
100 views

How accurate is a ripple counter (using D flip-flop) in measuring the frequency of a signal?

I have two oscillating signals S1 and S2 whose periods are always different by a very tiny amount (~10-50ps). Can I use a D-flip-flop ripple-counter to measure S1 and S2 individually, and then ...
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1answer
61 views

Understanding crystal resonator symbols - which one is 24Mhz?

So, I'm in need of a 24MHz crystal to drive an AVR microcontroller. I've got some crystals that I've desoldered off some old, useless equipment. I've found three crystals that have '24' on their ...
2
votes
1answer
73 views

Weird Voltage measurement problem

I have a DC/DC converter outputting 5.18 VDC @ 25% load (1 Ohm resistor). If I measure the voltage at the green nodes it fails out of tolerance, if I measure the voltage at the red nodes (before the ...
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2answers
153 views

Why do measurements displayed in multimeter inconsistently vary by factors of 1000 depending on range?

For my science fair project, I am measuring the resistance of a 100 foot piece of 32 gauge Nichrome wire. Using a Innova 3300 digital multimeter, I get the following results for each resistance range ...
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2answers
90 views

Need a simple circuit and IC for low voltage indicator

I have a battery operated power distribution system for some audio gear I use. I need to implement a multi-level voltage indicator via LED: Green when the voltage is above 14VDC Orange when the ...
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3answers
141 views

How to measure the temperature of a thin wire using a infrared (IR) thermometer?

I got a laser thermometer to measure the temperature of a wire for my science fair. However, when I attempted to measure the wire, it was too thin and I just measured whatever was behind it. How can I ...
2
votes
1answer
101 views

Calculate the appropriate bias voltage (and resistor) of a condenser microphone

I have a condenser microphone that has no any model name or number. As we know condenser microphones need a bias voltage for operation. Some microphones need \$2 V\$[1]. and some need more. As we can ...
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2answers
201 views

Measuring water pressure in a tank

I am trying to build a pressure sensor ( PSI gauge ) that will be used to measure and monitor the pressure in a pool water filter. These generally have a mechanical pressure gauge like this.... ...
4
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1answer
181 views

Measuring a smartphone's power consumption

Scenario: A smartphone (Nexus S) battery is charged via USB connection, connected with a laptop. A measuring device (USB Tester) is running between laptop and smartphone. Observation: The measured ...
5
votes
4answers
2k views

Can't get a precise reading with PT100 temperature sensor

I am trying to get more precise temperature value from PT100 ( 2 wire ) sensor with Arduino. Here's how my circuit looks like : When the sensor is about 20 °C I get a value on A5 pin that is 432 ...
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3answers
218 views

Measure capacitance in softwire using Tina/Multisim/other simulators

Is there a way to measure capacitance of a capacitive network as shown below in Tina-TI, Multisim, or other simulators? I tried searching but I couldn't find any way to measure capacitance directly as ...
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0answers
47 views

Accelerometers strange data

I am trying to read data from the Microsoft Kinects accelerometer, and I did a measurement where I rotated the Kinect really slowly around each axis, to get every possible g value from the gravity. ...
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2answers
50 views

Current measurement maximum time

On my multimeter I have two current measurement connection. One for the mA and one for the A. On the ampere one there's a time limitation but not on the mA one. Also they mention in the manual a kind ...
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2answers
69 views

Multimeter resistance measure

I've found this question but they don't talk about damage (Multimeter ranges) If I measure a 20KOhm resistance an I'm for example in the 200Ohm range, can this damage my multimeter ?
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1answer
71 views

How to measure the delay of one single inverter in ASIC?

In practice, is it feasible for a chip manufacture to reliably and accurately measure the delay of one single inverter in ASIC? If it is, how can one go about doing it?
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1answer
101 views

Measuring noise of audio preamp power supply

How does one measures noise/performance of audio preamp power supply?
3
votes
1answer
60 views

Is there a way to determine the pull-down resistance of a FPGA pin?

I have an FPGA and don't have access to the code used to program it. The data sheet specifies that you can configure pull-down resistors that vary from 50-100 ohms. Can you measure the value of a ...
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0answers
38 views

Average flux density in a standard pair of headphones? (AC fields only)

I don't have a teslameter to measure it, so can someone with expertise give an approximate as to what the flux density may be next to one speaker elements in a normal pair of studio earphones (not ...
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3answers
87 views

Can someone help understand what these different RF power detector specs mean?

I've been looking at various RF power detectors for a project I'm working on, but I don't quite understand what the manufacturers mean by "dB range". For example, the LT5534 Log RF Power Detector has ...
0
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2answers
116 views

What does pitch means in the context of the sizing of a breadboard?

I am trying to build an eagle-cad part for an Arduino Micro. (so I can make a PCB and stick the arduino on it) I was hoping to derive the distance between the two rails of pins from the fact that on a ...
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2answers
112 views

How do I measure the analogue in voltage of a ICL7136 using an Arduino

I have ICL7136 MQFC (the square one) chip driving an LCD display. it's measuring and displaying temperature data from a thermometer probe. I want to grab the analogue readings an log them with an ...
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4answers
255 views

Converting variable capacitance value to variable DC voltage level

I need a simple method to convert a small variable capacitance value into considerable variable DC voltage. Capacitance value range = 0nF ~ 14nF DC value range needed = 0V ~ 6V What I've tried ...
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1answer
84 views

Tilt sensor angle

I have a tilt sensor that acts sort of like a potentiometer. It is an electrolytic sensor that acts sort of like a balance. One side increases in voltage while one side lowers voltage. The sum of both ...
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2answers
70 views

zero'ing a tilt sensor

I have a tilt sensor where I want to measure a 10 degree angle. The 10 degree angle is on a machined ramp. The ramp has a built in "level" 0 degree section in it. Basically what I want to do is be ...
0
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1answer
65 views

Calculating specs of the Li-Ion battery depending on Robot's weight

I want to build a moving wireless robot. Vehicle needs to have a speed of 50 kms/hr and needs to have a tracks instead of wheels. The approximate weight (without the batteries) might range between 20 ...
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3answers
304 views

Simple measurment of resistance with microcontroller

What is a simple way to measure resistance (in this case 0-100 kOhm) using micro-controller (I'm using STM32, it has 12-bit ADC, timer, but no comparator). I want it simple (not too many components) ...
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0answers
74 views

Measuring distance of two objects in short range

Is there a solution for measuring distances of two object in short range? Max 1 meter of distance needed. Accuracy is not an issue e.g. accuracy of 1-2cm would be good enough. Solution should of ...