NIOSH 7400 METHOD NEWEST ACTUAL QUESTIONS

NIOSH 7400 METHOD NEWEST ACTUAL / QUESTIONS

WITH ANSWERS VERIFIED/GRADED A+

T/F: although confidence limit and control limit both are

abbreviated CL, at times they both can be the same value - --- -Answers---true

T/F: one must always observe 100 fields on a sample - ----

Answers---false (always 20 fields)

as a minimum occurrence, how often should recounts be

performed? one out of every: - ----Answers---10 (or 10%)

T/F: to prepare a permanent slide, one needs acetone and

triacetin which are mixed together in a 1:1 solution by volume -

----Answers---naaaahh, False

one of the liquids used to prepare permanent slides is: - ----

Answers---triacetin

T/F: as the count on a light sample increases, one expects the

variation associated with the count to increase also - ---- Answers---false

T/F: the HSE/NPL mark 2 test slide is used to investigate the

microscopes resolution - ----Answers---true

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the specified tolerance of a Walron-Beckett graticules field diameter is 100 + or - how many micrometers? - ---- Answers---2

a stage micrometer is used to test the resolution and contrast (overall image quality of the microscope) - ----Answers--- falso

for Kohler illumination, what are the three steps to calibrating your microscope? - ----Answers---1. focus on the sample

• Field Iris
• phase rings

how do you order a Walton Beckett graticule - ----Answers-- -1. take the actual diameter of W/B

• take the diameter of the glass
• order the W/B G-22

the numerical aperture range specified in method #7400 is: - -

---Answers---.65-.75

for the A counting rules, which version of the Walton Beckett graticule is used? - ----Answers---G-22

if the diameter of a Walton Beckett graticule is 100 micrometers, what is the field area in square millimeters? - -- --Answers---.00785 mm squared

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