Physics 116C, Spring, 2007
Lecture: MWF 1:10-2:00 PM, Rm. 158 Roessler.
Lab: Wed. 3:10-6 PM Rm. 152 Roessler.
Instructor: Prof. David E. Pellett, 337 Physics, (530) 752-1783.
Office hours: Mon. 3-4, Fri. 3-4 in 152 Roessler (subject to change), or by appointment.
E-mail: pellett (at) physics (dot) ucdavis (dot) edu
TA: Solomon Obolu, Rm. 436 Physics
Office hours: TBA
E-mail: obolu (at) physics (dot) ucdavis (dot) edu
Last updated Sun, Jun 10, 2007
Prospectus
Physics 116C
introduces techniques for making physical measurements using
computer-based instrumentation. We use the LabVIEW programming system,
which finds wide application in physics (and other) labs. The course
will also cover experimental techniques, statistical analysis of data,
the sampling theorem, finite Fourier transform techniques, noise
spectra and other issues beyond the programming language itself in a
series of lectures (see outline below). A brief overview of other
approaches to data acquisition and experiment control will be provided
at the end.
The course also includes physics experiments at
the level of Physics 122 which illustrate techniques developed in the
course. These will require complete reports.
The text by
Essick is essentially a series of well-illustrated exercises and
experiments for learning the LabVIEW language and applying it to
mathematical problems as well as to data acquisition. This will be the
focus of the first 6 weeks of the course (supplemented with related
lectures and the Geiger counter experiment). You will need to keep a
personal computer file with your work on these exercises in Essick
which can be checked by the TA during lab each week. This will be
considered as part of your lab work. You are encouraged to use the
student edition of LabVIEW on your own computer outside the lab times
to complete these assignments (let me know if you have a problem here).
Nonetheless, the initial labs will provide some time to work on the
exercises in Essick.
Prerequisites: Physics 9D, 116B, Math 22AB or consent of department
Web pages from other courses in sequence: Physics 116A, Physics 116B
Physics 116C Spring 2007 Outline
(Preliminary)
Week |
Monday |
Topics |
Lab plus Essick assignments for week |
0 |
(March 26) |
Course overview, LabVIEW Introduction
First day of class is Wed., March 28
(Cesar Chavez holiday Fri., March 30) |
First lab: Start Essick assignment:
Self-study exercises in Ch. 1 |
1 |
April 2 |
Introduction to Statistics
Statistics Notes I |
Essick self-study exercises Ch. 2-4
Lab computers available for LabVIEW exercises |
2 |
April 9 |
Error analysis; radioactive decay,
Geiger counters, etc. |
Lab: Geiger Counter, Statistics and Radioactive Decay (do statistics part this week)(rev 4/12/07)
Geiger counter VI (v 2)
LM311 comparator specifications Do Essick self-study exercises Ch 5-7 |
3 |
April 16 |
Least squares fits, Chi-square dist'n, confidence intervals
Statistics Notes II
|
Lab: Radioactive Decay and Mean Life
Prototype VI to read data from file, do Lev-Mar fit
Target Function and Derivatives VI for above Do Essick self-study exercises Ch. 8,9 |
4 |
April 23 |
25 min. Quiz 1 Mon. April 23
(note change of date)
DAQ hardware, A/D, D/A conversion
Sampling theorem, FFT, freq. spectra,
windowing; convolutions w.r.t. spectra
and statistical distributions
Statistics Notes III |
Do Essick self-study exercises Ch. 10 Lab: DAQ, Digital Oscilloscope, Spectrum Analyzer
Need Ch. 10 VI's for lab this week
Note: be sure to refer to the LabVIEW v. 6.1 updates (pdf file) for Essick's book. When
you set the channel input for the AI Group Config vi, you can set or
edit the various parameters for the channel (voltage range, input
connection type, etc.) and give it a name such as "Chan0" by
right-clicking and selecting the appropriate function from the menu. |
5 |
April 30 |
Fourier Notes I
PID process control
|
Digital Thermometer (Essick, p. 312)
See Week 5 Assignment for details
PID Temp. Controller (Essick, Ch. 11) |
6 |
May 7 |
Signal sources, grounding, shielding
Digital filters (intro)
MT Exam Wednesday May 9
|
PID Temp. Controller
See Week 6 assignment for details |
7 |
May 14 |
Noise spectra, Johnson noise
|
PID Temp. Controller |
8 |
May 21 |
Data busses, transmission lines
|
Johnson Noise Experiment |
9 |
May 28 |
Memorial Day holiday on Monday
GPIB and instrument control (Ch. 11)
Noise Notes
25 min. Quiz 2 Fri. June 1 |
Johnson Noise Experiment |
10 |
June 4 |
Other DAQ systems
Last 116C class is Wed. June
6 |
Johnson Noise Experiment |
|
|
Final Exam Mon., June 11
10:30 AM - 12:30 PM |
|
Texts:
- Essick, Advanced LabVIEW Labs, Prentice Hall, ISBN 0-13-833949-X.
- Essick developed this text for use in a year-long advanced physics laboratory course at Reed College.
- LabVIEW 7.0 Express Student Edition with 7.1 Update, includes software and book, Learning With Labview by Bishop, published by Prentice Hall, ISBN 0-13-188054-3.
- With this, you can use the LabVIEW language on your own computer (Windows or MacOS; student edition not available for Linux).
- Bevington and Robinson, Data Reduction and Error Analysis for the Physical Sciences, 3rd Ed., McGraw-Hill, ISBN 0-07-247227-8.
- This is a "classic" basic reference on data analysis for experimental physics.
- Note that there are also many reading assignments in Horowitz and Hill, The Art of Electronics, 2nd. Ed., the "classic" reference on electronics for experimental physics and a required text for Physics 116B.
References:
- Melissinos, Experiments in Modern Physics*
- Horowitz and Hill, The Art of Electronics, 2nd. Ed.*
- Squires, Practical Physics*
- Johnson and Jennings, LabVIEW Graphical Programming, 3rd Ed.
- Hamming, Digital Filters*
- Jacquot, Modern Digital Control Systems, 2nd Ed.
- Press et al., Numerical Recipes in C* (see below)
________
* On reserve in Shelds Library (Melissinos may not be there yet)
Other references (here or on the web):
- Probability, Statistics, Least Squares Fits etc.
- Radioactivity and Particle Detectors
Grading: 7% Quiz 1, 14% MT, 7% Quiz 2, 38% Lab, 10% HW, 24% Final.
Course Syllabus (to be added)
The .pdf files require Adobe Acrobat reader.
RSS Feed:
To get the Physics 116 news feed, which I use for listing announcements
as they are posted, you need to enter the following URL: feed://www.physics.ucdavis.edu/Classes/Physics116/rss/Physics116.xml.
Assignments
Assignment 1 – Do by 4/7/07: Work through Ch. 1-4 of Essick; read Bevington, Ch. 1-3
- Problems due in lab on Wednesday, April 11: Bevington, problems 2.9, 2.13, 3.1(b,d,e - assume u and v are uncorrleated) plus the following:
- Construct a LabVIEW VI based on this "skeleton" VI (save as Hist_Prob.vi)
to make a histogram of the student scores in Problem 1.5 of Bevington
and calculate the mean and population standard deviation. Use the
LabVIEW General Histogram VI and the Standard Deviation and Variance VI
provided in the skeleton (some inputs have been provided). Provide an
input control array for the data. Also provide controls for the
histogram minimum, maximum and number of bins (set them at 0, 100 and
20, respectively, for your VI). You do not connect anything to "Bins,"
"# Outside" or "Error" for the histogram. Look inside the Standard
Deviation and Variance VI to verify that it is calculating these
quantities correctly.(Note: here is a version saved for LabVIEW 7.0. Let me know if it works or not)
- Prob. 2.3 in Bevington (you don't need to repeat for p=1/6)
or optionally, do this instead: Make a LabVIEW VI to make an x-y plot (bar chart) of a general binomial distribution P(x;n,p)
with n and p as inputs. Also output the array of values. Note that
there is a VI to calculate binomial coefficients. You will need to use
a FOR loop to calculate the array of probabilities. Then use this to do
Prob. 2.3. - LabVIEW provides a unit normal cumulative distribution
called "Normal Dist." The LabVIEW "help" description explains what it
does. Make a LabVIEW VI to calculate the Gaussian probability PG(a<x≤b;
μ,σ). Have your VI read values for a, b, μ and σ from front panel
controls and output the result on a front panel indicator. Test your VI
with values based on Table C.2 in Bevington.
- Problem Solutions
Assignment 2 –
Do by 4/13/05: Essick self-study exercises Ch 5-7; read Bevington, Ch.
4-6 as background material for topics discussed in class and used in
the experiments on radioactive decay. Some of Bevington can be read
"once over lightly." The main emphasis in Ch. 5 is random number
generation and generation of Gaussian distributions. Other information
on distributions (such as cumulative distribution function) is in the
class notes or in the Particle Data Group information in the web links referenced above.
- Problems due Friday, April 20: Bevington, problems 3.7, 4.5 and 4.6(b) plus
- this special problem (rev. 1) based on Bevington, Prob. 4.13 (not 4.13 itself). Here are the Gaussian Comparison VI's (v. 7.1 and 7.0) (to modify) and data (text file) for the problem.
- This
VI can be modified for use with your Gaussian Geiger counter data.
Since the mean and standard deviation of the parent distribution are
not known, sample values must be used and the number of degrees of
freedom reduced accordingly. Also, the variance for each bin is taken
to be the contents of the bin: σj2 = h(xj). See Table 4.2 in Bevington (columns marked "From sample distribution")
- Bevington solutions and special LabVIEW problem solution.
Assignment 3 – week of 4/17: Essick self-study exercises in Chapter 8; start Chapter 9.
- Essick Ch. 8 covers least squares fits (including the nonlinear Levenberg-Marquardt method), which you also need for the radioactive decay experiment in lab. Also read Bevington:
7.1-7.2 (error matrix). Try to get the flavor of Ch 8 on nonlinear
least squares fits and error matrix estimates including the
Levenberg-Marquardt method. Also read 11.1 (chi-square distribution)
and the section on confidence levels for a one-parameter fit in Sec.
11.5. (For optional further study, Ch. 7 covers polynomial fits;
Ch. 8, fitting nonlinear functions; and the remainder of 11.5,
confidence levels for multiparameter fits.)
- Essick Ch. 9
covers Fourier transforms, aliasing, windowing and how to interpret
discrete sampled spectra. I will discuss Fourier transforms and the
sampling theorem in class. Brief notes on sampled signals and Fourier transforms are here. A convolution theorem worked example is here.
- Notes on upcoming 25 min. quiz (Monday, April 23):
- Open books (Essick, Bevington). Bring a calculator.
- Covers Ch. 1 through 4 of Bevington, Ch. 1 through 6 of Essick.
- Quiz 1 with solutions here.
Assignment 4 – week of 4/23 (based on Week 4 of the Course Outline, above):
- Continue working through the exercises in Essick.
Ch. 10 introduces DAQ hardware and has exercises to produce a digital
oscilloscope and a spectrum analyzer. It also has a digital thermometer
project (to be done next week).
- The lab this week (April 26) is on the DAQ system, Digital Oscilloscope and Spectrum Analyzer (Essick, Ch. 10).
This will provide time for you to work on and, we hope, complete the
exercises in Ch. 9 and 10 (up to but not including the digital
thermometer) Concentrate on getting the digital oscilloscope VI to work
and address the questions in the text.
- DAQ Hardware: the computers have either National
Instruments PCI-6052E or PCI-6030E multipurpose I/O (MIO) boards. They
are similar but the 6052E has a maximum sampling rate of 333 kHz vs.
100 kHz for the 6030. The I/O connections are like the E Series MIO-16
on p. 283 of Essick (connections are available on the front panel of
the box on the bench). Here is an overview of the E-series MIO boards with basic block diagrams and specifications.
- Further information on NI DAQ systems - here is a tutorial from National Instruments on making analog connections (differential, single-ended, etc. - will discuss in class later)
Assignment 5 – week of 4/30:
- In
Assignment 3, I said I would discuss Fourier transforms and spectral
analysis in class. This is the week. Here is relevant material copied
from Assignment 3:
- Homework assignment here (pdf file) due Monday, 5/7/07
- Help on Prob. 2: Here is a prototype VI: Dist_Plot v. 7.1, v. 7.0) for you to modify (it plots a uniform distribution now).
- Homework problem set 3 solutions
- The lab writeup for the Geiger Counter, Statistics and Radioactive Decay lab is due in class Friday, May 11. Here are some additional guidelines on the writeup.
- The upcoming labs
(weeks 5 and 6) concern measuring temperature using a thermistor
(Essick, Ch. 8 and p. 312) and manipulating the temperature of an
aluminum block with a PID temperature controller (Ch. 11 and Appendix
I).
- This week: read this material in Essick
before coming to lab. In particular, analyze the operation of the
circuit on p. 312 (remember the Op-Amp "golden rules." You will build
this and write the appropriate VI to measure temperatures. You should
also start on the VI for the PID controller (only general guidelines
given).
- Keep up your individual lab notebook for this project.
This lab (Digital Thermometer and PID Temperature Control) will require
a brief writeup when you are finished.
- Here is a file with resistance vs. temperature data for the thermistor we will use. Use this instead of the R vs. T data in the text.
- Set up the analog input of your VI for "Referenced Single-Ended" and set the switch on the connector panel accordingly.
- More information on temperature measurement and thermistors:
- Horowitz
and Hill (H&H), Ch. 15 has a good overview of many measurement
transducers and techniques. There is a discussion of thermistor and
thermocouple accuracy in H&H, Sec. 15.01. They state that
thermistors are available with "tight conformity (0.1–0.2° C) to
standard curves." This is better than what they claim for thermocouples
(0.5 to 2° C). Here is a quick guide from the web which compares thermocouples, thermistors and a third device, the resistance temperature detector (RTD).
- Here is the datasheet
on BC Components negative temperature coefficient (NTC) thermistors
covering the device we use (2232 640 5 5103). It contains data needed
to estimate temperature measurement accuracy (see the the next
reference).
- Here is a thermistor selection guide discussing the Steinhart-Hart equation and thermistor accuracy from Vishnay, a corporation which acquired BC Components in 2002.
Assignment 6 – week of 5/7:
- Important information on upcoming midterm exam Wednesday, May 9:
- The LabVIEW component will be take-home this time.
The (short, hopefully) problem will be posted on this web site at some
time Monday, May 7 and will be due Wednesday. The rest of the exam
should not take the entire hour. You are expected to do this by
yourself.
- The exam will be open books (Essick, Bevington) plus one 8.5 in by 11 in sheet of paper of notes. Bring a calculator.
- I will provide the table of Fourier transform pairs (as on p. 3 of the last homework assignment).
- Covers assigned material
in Bevington (summarized in the posted statistics lecture notes I-III).
The key material is in Ch. 1-4(basics, distributions, propagations of
errors), bits of Ch. 5 (generating uniform and Gaussian (pseudo)random
numbers as in LabVIEW example), Ch. 6 (maximum likelihood and least
squares fit), Sec. 7.1-7.2 (error matrix) and Sec. 8.4 (Marquardt
method). You should know how (and when) to use Tables C.2 (for Gaussian
distribution) and C.4 (for chi-square distribution).
- Covers assigned material in Essick (through Ch. 10 - but basics
of sampled signals, Fourier transforms and convolution theorem only)
plus the notes on sampled signals and Fourier transforms (including
convolutions) posted on this page.
- Here is last year's midterm (a handy source of problems for homework).
- PID controller lab:
- Information about thermoelectric devices from Tellurex
- Once you have your controller working, you should investigate the PID controller performance.
- Before turning on the controller, check the thermistor temperature reading at room temperature using a thermometer provided.
- Measure and record the current going to the thermistor (don't rely on calculations).
- If
you haven't done so already, add a "waveform chart" display of the
temperature as a function of time. Then investivate the effect of the
parameters on the waveform. Here are suggestions on tuning the parameters. Further information on the PID algorithm as applied to oven control (heater only) is also available from the site.
- If
possible, add the possibility of inhibiting the integral term until you
are close to equilibrium. Otherwise, it takes a long time to overcome
the accumulated error when changing the set point.
- For your (brief) writeup, include an
overview of the PID algorithm, your circuit and VI diagrams, a
discussion of the performance of the system and a plot of temperature
vs. time showing behavior after changing the set point.
- Here is a checklist of points to address in you lab writeup.
- The
lab writeup will be due Friday, June 1. Turn it in in class or in my
mailbox across from the Physics office before 5 PM on June 1.
- Digital filters: Introductory notes are posted here.
- Reference on Digital Filters – Hamming, Digital Filters (on
reserve in the library): Secs 1.1-1.3, 2.1-2.7, 3.1, 3.9, 3.10. You may
also be interested in skimming Ch. 12 for an overview of recursive
filter analysis and the design of a Butterworth filter.
- Reference on relation to digital control system design: Jacquot, Modern Digital Control Systems, Ch. 4.
- Take Home Problem for Midterm Exam: (Due no later than the beginning of lab on Wednesday, 5/9). Work this one by yourself. Send e-mail to me if you get stuck on something.
- Miderm exam and midterm exam solution (including LabVIEW part, worth 50 points).
Assignment 7 – starting week of May 21:
- Reading assignment:
- Transmission lines: Class notes plus Horowitz and Hill, Sec. 13.09.
- Noise in electronic circuits: Horowitz and Hill, Secs. 7.11–7.22, plus material below related to the Johnson Noise lab.
- Homework assignment, due Wednesday, May 30 here.
- Johnson Noise Lab: The
goal of the lab is to make a plot of output noise power times BW vs. R.
The slope will be used to determine Boltzman's constant, k. We will also compare the results with the expected Johnson noise from the resistors and the amplifier.
- Here is the writeup for the Physics 122 Johnson noise experiment.
- Reference for the procedure and circuit we will use:
- Melissinos and Napolitano (M&N), Experiments in Modern Physics, 2nd. Ed., Sec. 3.6, "Measurements of Johnson Noise."
- Our circuit (available here with additional notes) uses a different low-noise op-amps from the ones indicated in the reference. We use the LT1793 op-amp for the first stage and the AD797 for the second stage. An LF411
is used to make a 2-pole Butterworth low-pass filter (see Horowitz and
Hill, Secs. 5.06 and 5.07). Note that the LT1793 has low voltage noise
and extremely low current noise specifications. This will allow us to
use relatively large resistance values where the thermal noise from the
resistor will greatly exceed the amplifier contribution.
- The Johnson Noise Test Fixture (JNTF): for this
experiment, you will use a pre-built circuit for the amplifier and
filter for better performance and to save time wiring (the circuit diagram is here).
It has +15 V, -15 V and ground connections (wires color-coded to match
the binding posts on the circuit test boards), a BNC output jack and a
threaded SMA input connector for the calibration signal or for an
external resistor. A multiple positiion switch allows you to connect
one of the following 0.5% metal film resistors to the input (note the
labels differ from the actual values in some cases):
Label |
Short |
300 |
1K |
3K |
6K |
10K |
30K |
60K |
100K |
500K |
1M |
Ext |
Actual Resistor Value |
0 Ohms |
301 |
1.00 K |
3.16 K |
6.03 K |
10.0 K |
24.3 K |
60.4 K |
100. K |
499 K |
1.00 M |
SMA Input |
- Key points for measurement (see our circuit diagram):
- Measure
and plot g(f), the gain of the amplifier as a function of frequency,
using the function generator, voltage divider and oscilloscope or
oscilloscope VI. Be sure the low frequency and high frequency corner
frequencies are as expected (16 Hz and 16 kHz, respectively) and that
the gain is down by an order of magnitude by the Nyquist critical
frequency (50 kHz).
- Connect the circuit output to the NI ADC using a
nonreferenced single-ended (NRSE) input with voltage range from -0.1 V
to 0.1 V.
- The power spectrum will be measured using a suitably modified
version of the FFT Magnitude Only VI on p. 256 of Essick. This does the
one-sided amplitude distribution already. The number of points should
be 1024 as before (or 4096) but the sampling frequency should be 100000. The spectrum should extend from 0-50 kHz in bins 0-512 (0-2048 if you use 4096 bins).
- Modification: the VI as written gives A(fi)+A(-fi)=2A(fi) for each frequency.
As stated below, we want to find A2(fi)+A2(-fi)=2A2(fi)=(2A(fi))2/2 instead, so you must change the VI accordingly.
- Start
with the100 kilohm 0.5% metal film resistor as the noise source. The
spectrum should have the same shape as your amplifier gain vs.
frequency curve if the signal is dominated by Johnson noise (either
from the amplifier or the resistor). There may be some additional
pickup of signals from 60 Hz AC (and harmonics). These should show up
as peaks at the low end. But there should be a region which is fairly
flat within the amplifier bandwidth (perhaps from approx. 1 kHz to 7
kHz – calculate which channels correspond to this frequency interval).
If there is excessive interference, check the wiring.
- The sum of the squares of the amplitudes of the FFT components within these limits (f1 to f2) will correspond to a measurement of <V2>, the mean squared output voltage in that bandwidth. For an explanation, refer to these notes.
- For
each resistor value, you will need to sum the channels of interest for
a single measurement. Repeat at least N=10 times to get a mean value
for <V2> and an estimate of its standard deviation, sigma. The error in the mean value of <V2> will be sigma/(square root of N). You should automate this procedure in your VI.
- Repeat for other resistor values available in the JNTF.
- Find and plot <V2> vs. R with errors and fit to a straight line (two parameter fit).
- This linear fit corresponds to the function <V2> = (eA2 + 4kTR)G2(f2-f1), where
- eA2 represents the noise contribution from the amplifier (amplifier current noise component should be negligible with LT1793)
- G2
is the average of the square of the gain of the amplifier g(f) over the
frequency range used. If you use the range 1 kHz - 7 kHz, this should
be reasonably constant.
- or, alternatively, if g(f) is not sufficiently constant over your interval, find G2(f2-f1) = Integral from f1 to f2 of g2(f) df. You can calculate this numerically from your g(f) data (you could use Simpson's rule).
- Be sure to measure the ambient temperature, T.
- The parameters eA2
and Boltzman's constant k can be found from the fitted parameters. Find
the errors in these quantities from the fit covariance matrix (using
propagation of errors as appropriate).
- Compare with the accepted value of Boltzman's constant.
- Compare eA with what you expect from the op-amp specifications in a non-inverting amplifier configuration (see Horowitz and Hill, p. 447).
- Reference for the procedure and circuit: Melissinos and Napolitano (M&N), Experiments in Modern Physics, 2nd. Ed., Sec. 3.6, "Measurements of Johnson Noise."
- Notes on upcoming 25 min. quiz (Monday, April 23):
- Open books (Essick, Bevington) plus two 8 1/2" x 11" sheets of notes. Bring a calculator.
- Topics:
sampled waveforms, Fourier transform (including FFT), DAQ basics,
instrumentation amplifiers, grounding and shielding, transmission line
basics, noise basics.
- Assignment 7 problem set solutions here.
- Quiz 2 solution here
Assignment 8 – week of 6/4:
- Information on Johnson Noise Lab Writeup:
- The report can be brief but should cover the points outlined here (revised 6/6/07). Refer to the information in Assignment 7 (above) for details.
- Lab Report is due
at 5 PM on Monday, June 11 no later than Thursday, June 14 at 5:00 PM. (Note change.)
- Upload
the LabVIEW VI you used and any data files to your SmartSite folder. If
you have your report in pdf format, you could upload it as well.
- Important (added 6/7/07): if you were unable to
get Johnson noise data by the end of the last lab on Wednesday, you
should use the data below provided by M. Saxon, J. Moats and N. Heller:
- Revised noise data (Excel format and csv format). The previous version had incorrect values for G2 and its error - use this version. The <V2> values are the same as before. The columns are labeled appropriately.
- As usual, there may be additional sources of error besides the given statistical errors.
- You
should analyze your own data to the extent possible. For example, if
you made your own gain measurements, you should provide them and
compare with the data provided above (including errors). It would also
be good to compare the measured midband gain with what you would expect
from the two op-amps and filter circuit in the circuit diagram.
- Remember to upload the VI's you used, even if they are not complete.
- Final Exam Information:
- The exam time is Monday, June 11 from 10:30-12:30.
- The
exam will cover the entire course (including labs) with some emphasis
on material since the midterm exam. The exam will not cover digital
filters.
- You may refer to
- Two books (Essick and Bevington)
- Three 8.5 in by 11 in pages of your own notes
- The 3 sets of notes linked here:
- The Fourier transform page (last page of the Midterm Exam) will be supplied with the final.
- Bring a calculator.
- Here is a copy of last year's final (to show scope and format - no solution available; sorry.)
- Special Office Hours: Sunday 6/10/07 4-5 PM in the Physics 116 lab, 152 Roessler.
- Information on topics for further study (will discuss briefly on last day of class):
- Use of the General Purpose Interface Bus
(GPIB) (also known as IEEE-488) to connect instruments is covered in
Ch. 12 of Essick. Many commercial laboratory instruments have a GPIB
interface and a ready-made LabVIEW VI to provide a quick start for a
data acquisition system.
- Further GPIB information:
- Additional information on other busses and real-time operating systems:
- Horowitz and Hill, Secs. 10.15, 10.19, 10.20, 10.21 (needs updating since this field evolves rapidly).
- VME FAQ
VME is a bus which is widely used in high energy physics applications,
particularly realtime applications (see below). It was originally
developed by Motorola for use with the then-new M68000 processor family
to build specialized DAQ systems. Many other processors are now
available along with a wide variety of I/O and other boards. A variant
of VME, the VXI bus, (Vme bus eXtensions for Instrumentation) incorporates some GPIB features but builds on VME to achieve faster performance.
- Comp.realtime frequently-asked questions
- General computer bus comparisons
- Information on Comedi (Linux control and measurement device interface) drivers which allow use of various DAQ boards (including some NI boards) with Linux and C-language programs.
Announcements
3/20/07:
Preliminary Physics 116C information is posted here including the texts
to be used. The course outline has been updated. Links to the previous
Physics 116A and 116B web pages are also provided.
4/3/07: A problem assignment including some LabVIEW
exercises has been posted under Assignment 1. It is due in lab on
Wednesday, April 11. The next reading and Essick assignments have also
been posted.
4/10/07:
- The
lab writeup for Weeks 2 and 3 has been updated to include the revised
trigger circuit, an improved procedure and relevant information from
the corresponding Physics 122 experiment.
- Further notes on the problem assignment: (a) in Prob. 3.1 of Bevington, assume u and v
are uncorrelated; (b) bring your homework VI's to lab in the same way
you have done with your Essick assignments (e.g., USB flash drive or
via MyUCDavis).
4/11/07:
A further update has been made to the lab writeup (mainly discussing
the histogram binning). Also, a VI for Assignment 1 Prob. 1 has been
added which is supposed to be compatible with LabVIEW v. 7.0.
4/13/07: A new problem set has been added, as discussed in class today. It is due next Wednesday in lab.
4/14/07: Part (d) of the special problem was revised (on degrees of freedom). I'll discuss this more on Monday.
4/17/07:
The due date for homework assignment 2 has been changed to Friday,
April 20. Quiz 1 has been moved to the following Monday. Also new
reading assignments have been posted (Assignment 3).
4/19/07: Solutions to Prob. Set 1 posted under Assignment 1.
4/22/07: Solutions for Bevington problems and special LabVIEW problem solution posted under Assignment 2 above.
4/25/07:
A note was added for the Week 4 Lab to remind you to check the Essick
updates for revisions to the DAQ vi's plus information on setting up
input channels.
4/29/07: Various information, announcements and changes:
- Midterm exam moved to Wednesday, May 9.
- Geiger counter, statistics and radioactive decay lab due in class Friday, May 11. Further information on the writeup is posted under Assignment 5.
4/30/07: Problem set 3 posted under Assignment 5 (above) due Monday, May 7.
5/3/07: The web site has been updated with information about
- The homework assignment: a prototype VI has been added
- The Geiger counter lab: a prototype VI for Gaussian comparisons (must be modified) and information on the Geiger tube
- The upcoming exam (including a copy of last year's midterm)
- The books on reserve in the library
- The assignment for next week
5/7/07: Solutions to Problem Set 3 have been posted under Assignment 5, above.
5/7/07: LabVIEW take-home exercise for midterm exam has been posted.
5/17/07:
Solutions to the midterm have been posted under Assignment 6, above.
Information on Peltier devices and a checklist for the PID Temperature
Controller lab writeup have also been added to the PID lab section of
Assignment 6.
5/21/07: Quiz 2 rescheduled for Friday, June 1.
5/22/07:
Assignment 7 has been posted on this site. It describes the Johnson
noise experiment which begins this week. It will be discussed in class
starting Wednesday, 5/23. Some problems will be added later.
5/23/07:
- A problem assignment due Wednesday, May 30 has been posted under Assignment 7, above.
- Information on upcoming quiz also posted under Assignment 7.
- The
PID temperature controller lab writeup will be due Friday, June 1. Turn
it in in class or in my mailbox across from the Physics office before 5
PM on June 1.
- Some clarifications have been made in the Johnson Noise
lab description and its linked notes. Most important: The power
spectrum will be measured using a suitably modified version of
the FFT Magnitude Only VI on p. 256 of Essick. The location of this VI
had been given incorrectly before, although I indicated the correct one
in lab on Wednesday.
5/29/07: As announced in class last Friday, there will be a special office hour today in the 116 lab from 5-6 PM.
5/30/07:
- The solutions for the Assignment 7 problem set have been posted at the end of Assignment 7, above.
- The PID lab deadline has been extended until Monday, June 4. Turn it in in class or in my mailbox across from the Physics office before 5 PM on June 4.
- Solution to Quiz 2 posted under Assignment 7.
- Guidelines,
due date and other information about the Johnson Noise lab have been
posted under Assignment 8. Also clarifications have been made in the
information about the lab in Assignment 7.
6/5/07: Information about the final exam has been posted under Assignment 8.
6/6/07: The checklist for the Johnson noise lab was revised to remove one of the items.
6/7/07:
- If
you were unable to get Johnson noise data by the end of the last lab on
Wednesday, you should use the shared data posted under Assignment 8.
- Special Office Hours: Sunday 6/10/07 4-5 PM in the Physics 116 lab, 152 Roessler.
6/7/07: If you are using the shared data, there has been a correction in the value for G2 and its error. Please download the data files again to get the correct values. The <V2> values were OK.
6/10/07:
After talking to some of the students in today's office hours, I have
decided to extend the deadline for the last Physics 116C lab. Instead
of Monday at 5 PM, it must be turned on or before 5 PM on Thursday,
June 14. It seems that many people have two finals tomorrow.
Links to topics relevant to class/lab
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