physics

A bothersome feature of many physical measurements is the presence of a background signal (commonly called "noise"). In Part 2.2.4 of the experiment, some light that reflects off the apparatus or from neighboring stations strikes the photometer even when the direct beam is blocked. In addition, due to electronic drifts, the photometer does not generally read 0.0 mV even in a dark room. It is necessary, therefore, to subtract off this background level from the data to obtain a valid measurement. Suppose the measured background level is 4.9 mV. A signal of 20.3 mV is measured at a distance of 29.5 mm and 17 mV is measured at 33 mm. Correct the data for background and normalize the data to the maximum value. What is the normalized corrected value at 33 mm?

  1. 0
  2. 0
  3. 23
asked by anna
  1. The background-corrected light measurement at 29.5 mm is 20.3 - 4.9 = 15.4 mV

    The corrected light measurement at 33 mm is 17.0 - 4.9 = 12.1 mV

    You need the maximum signal to normalize the data. You have not provided that data.

    1. 0
    2. 0
    posted by drwls
  2. 12.1/15.4= .785

    ^from drwls's answer above

    1. 0
    2. 0
    posted by KelseyO

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A bothersome feature of many physical measurements is the presence of a background signal (commonly called "noise"). It is necessary, therefore, to subtract off this background level from the data to obtain a valid measurement.

    asked by Marissa on October 9, 2009
  2. Physics

    In the experiment, a meter is hooked up to a speaker to monitor the amplitude of the received sound. Suppose the background signal level is 15 mV, the signal is 90 mV with no attenuator and is 30 mV with an attenuator in place.

    asked by Michael on November 16, 2011
  3. Physics

    In the experiment, a meter is hooked up to a speaker to monitor the amplitude of the received sound. Suppose the background signal level is 15 mV, the signal is 90 mV with no attenuator and is 30 mV with an attenuator in place.

    asked by Michael on November 28, 2011
  4. chemistry

    What type of feature will be observed in the EI mass spectrum of chlorobenzene? An absorption at 3100 cm–1 No signal at all A signal at 112 and a signal at 114 in a ratio of 3:1 A signal at 112 and a signal at 114 in a ratio of

    asked by Tiffany on December 12, 2011
  5. Chemistry

    Why wasn't information about the mass of isotopes sufficient for identifying the isotopes? Provide an example to explain the answer. Figure 2 shows 2.5 min averaged spectra of ambient aerosol at nominal m/z 208 obtained with the

    asked by Joe on October 28, 2017
  6. World Geography

    1.The physical feature of Western Europe where most major cities are found is called A. the plains. B. the glacier.

    asked by bree on April 8, 2013
  7. Social studies

    13.the physical feature of western europe where most major cities are found is called A.the plains (MY ANSWER) B.the glacier C.the tundra D.the taiga 14.what made the rhine river one of europes most polluted rivers? A.urbanization

    asked by LOVE on March 29, 2016
  8. Geography

    which of the following is an example of a physical feature on earths surface? a) Golden Gate Bridge b) Grand Canyon c) San Diego Zoo d) Sea World Physical features are not man-made. What do you think the answer is?

    asked by feroz on March 16, 2007
  9. self regulated volume control

    Hey what's up... does anyone know what does ''self regulated volume control'' mean? I suspect this is what is more commonly called AGC, or automatic gain control. This self regulating amplifer stage compensates for incoming signal

    asked by Piero on August 12, 2005
  10. astronomy

    on a domestic gas cooker the temperture in the hottest part of the flame is about 2200k.if salty eater is spilled in the flame then it becomes yellow-orange.measurements with a spectrometer show the presence of an emission line at

    asked by amy21 on March 3, 2008

More Similar Questions