1-6
BenchMike Pro 2025/2050 & Z-Mike Pro 4025/4050 Instruction Handbook: Introduction
The average of all the readings taken during a batch is calculated,
along with the standard deviation. The standard deviation is a
measure of how the individual sample values varied during the
batch. The standard deviation value indicates whether samples
were evenly distributed over a wide range of values or whether most
samples were grouped around the average value. The diagram to
the right shows two sample normal distributions.
The drawing to the right shows a normal distribution of data. A nor-
mal distribution is one in which 99.73% of all
values fall within ±3 standard deviations of
the average.
1.6
Laser Safety
The BenchMike Pro uses a Collimated Diode laser which emits red light at a wavelength of 635nm, while the Z-
Mike Pro uses a Helium-Neon gas laser, which emits light at a wavelength of 632.8nm. In each case, no invisible
or otherwise harmful radiation is emitted.
The radiant output power of the internal laser and of the entire BenchMike Pro is relatively low. The laser beam
will not harm your skin, and your eyes are protected by a natural aversion response that will cause you to blink or
look away. However, the laser light emitted from the BenchMike Pro should be treated with caution and common
sense. Do not attempt to look into the BenchMike Pro, and avoid staring at reflections of the beam.
The American National Standard for the Safe Use of Lasers (ANSI Z136.1
—1993) classifies this laser product as
Low Power
— Class II and provides reasonable and adequate guides for its safe use. The user of the BenchMike
Pro and other personnel responsible for its safe use should consult this ANSI standard. It is available from:
American National Standards Institute
1430 Broadway
New York, New York 10018
The Center for Devices and Radiological Health (CDRH) of the Food and Drug Administration has established
regulations for manufacturers of laser products. All laser products sold in the U.S.A. since August, 1976 must be
certified by the manufacturer as meeting certain product performance (safety) standards, and each laser must
bear a label indicating compliance with the standard and denoting laser hazard classification.