Munsell Test / Color Vision Test SOP – Standard Operating Procedure

by | Apr 29, 2019 | LAB

Munsell Test

Purpose & Scope: The Farnsworth-Munsell Test offers a simple method for testing color discrimination. It yields data which can be applied to many psychological and shop floor problems in color vision. Its primary uses are to:

Separate persons with normal color vision into classes of superior, average and low color discrimination.To measure the zones of color confusion of persons dealing in color shades.

Responsibilities

QA In-charge is responsible to monitor and to ensure that all the persons dealing with color shades are tested for color vision IQC in-charge is responsible for conducting the test, communicating the results and maintains the records.  

Procedures

Material:The FM Hue Test includes a total of 93 colors mounted in plastic caps,housed in four separate cases. Each case consists of two hinged panels which contain a quarter of the 85 numbered, removable color caps. (Two caps are repeated and fixed as pilot colors at either end of one panel in each case, making a total of ninety-three caps.)If the caps become severely smudged or damaged, they should be replaced.With normal usage, it is recommended that the caps be replaced every four years.

Lighting

Test should be carried out under Day Light D65 in the light box.Since natural daylight is variable, the results cannot be expected to be as stable as when the test is given under standard illumination.Ordinary incandescent room lights should be switched off or shielded from the test area.

Testing

  • Open one case and arrange the caps in random order
  • Instruct the person being tested as below :
  • to arrange the caps in order according to color and place them so they form a regular color series between the two end caps (indicate)
  • It should take you about two minutes per panel. However, accuracy is more important than speed so you will be told when the two minutes are up but the panel will not be taken away from him/her.
  • To Allow the person as long as necessary to arrange the caps in an order with which they are satisfied.
  • If two minutes have passed, and the person is not through, quietly remind them that two minutes are up, and allow more time to finish the task.
  • Repeat the process for rest 3 cases.
  • Record the time taken to complete the test.
  • Enter the findings into FM Hue Test Scoring Software.

Testing receiver

  • Only Quality people will receive this test for all the department like Store, Sample, sewing, cutting, Finishing & packing etc. .
  • Result Analysis
  • Person with ‘normal’ color vision can be classified as follows:
  • Superior Discrimination
  • About 16% of the population (exclusive of color defectives) has been found to make 0 to 4 transpositions on first test, or
  • total error score of zero to 16. This is the range of superior competence for color discrimination.
  • Average Discrimination
  • About 68% of the population (exclusive of color defectives) make a total error score between 20 and 100 on first tests. This is the range of normal competence for color

Discrimination

  • Low Discrimination
  • About 16% of the population (exclusive of color defectives has been found to make total error scores of more than 100. The first retest may show improvement, but further retests do not materially affect the score. Repeated retests reveal no region of large maximum or minimum sensitivity as is found in color defective patterns.
  • Total error scores represent the color discrimination ability of an individual at a given point in time.
  • It is possible that color discrimination ability for that individual may improve at a later time as a result of further training and experience.
  • Identifying the color defectiveness:
  • The pattern of color defectiveness is identified using the FM Hue Test by bi-polarity, a clustering of maximum errors in two regions which are nearly opposite.
  • The severity of the defect can be gauged by the extent of the ‘bulge’, a severe degree of defect showing clear bipolarity with high error scores; moderate cases show small ‘bulges’ and lower total error scores; mild cases with good color discrimination may show no ‘bulge’
  • The position of the mid-point of the errors in the pattern will identify the type of color defectiveness as below :
  • Protans : have a mid-point between 62 and 70
  • Deutans : have a mid-point between 56 and 61
  • Tritans : have a mid-point between 46 and 52.
  • To handle the shades, the person has to score minimum Average
  • Discrimination.
  • If someone scores, poor discrimination, the test may be re-conducted after six months with proper training.
  • When new QA/QC will be selected at first he/ she will do The munsell test , Any color blind person not allow to work  .
  • Every QA /QC will get Munsell test randomly after one year.