Page 3 Model 205ce and 205Mce Operation Manual
OPERATION
1. Depress the OFF/ON switch to power the
instrument “ON”.
2. Select then depress one of the black
Amplitude Measurement buttons:
ACC = Acceleration = g’s (peak)(in/sec²)
205Mce = g’s mm/sec²
VEL = Velocity = Inches Per Second (peak)
205Mce = Velocity = mm/sec
DISP = Displacement = Mils (peak to peak)
205Mce = Displacement = µm
3. Select then depress one of the gray Range
buttons (2, 20, 200 or Very Low
Range)(205M ce = 20, 200, 2000 or Very
Low Range). Change the Range button to
another range if necessary until the
AMPLITUDE meter reads without indicating
an overrange condition.
4. Over Range:
Display = 1 __ __ __ [1 with 3 blank digits]).
5. Read vibration amount directly.
Accelerometer - Model 601
The Balmac Model 205 ce Vibration Meter uses
the Model 601 Accelerometer. The 601 is a
compact, general purpose 100 mV/g
Accelerometer for direct measurement of
vibration amplitude. The pickup’s axis of
sensitivity is perpendicular to the mounting base.
The pickup may be used and mounted in any
direction (horizontal, vertical, axial).
The best recommended permanent mounting
method is using a 1/4-28 UNF stud on a clean
flat surface, or the Model 052 Magnetic Base.
CAUTION: The mounting stud must not extend
into the pickup more than 0.2". Hand tighten the
pickup. DO NOT WRENCH THE PICKUP
ONTO THE MOUNTING.
NOTE: DO NOT SLAM OR BANG THE
ACCELEROMETER WHEN MOUNTING WITH
THE MAGNETIC BASE. THIS CAN DAMAGE
THE PICKUP.
MEASUREMENTS
VELOCITY is the recommended setting for
machinery severity vibration readings with the
Model 205 ce Vibration Meter. The destructive
forces generated in today’s higher speed
machines are more proportional to vibration
velocity than either displacement or acceleration.
For example, it is very unusual for someone to
arrive on the scene of an automobile accident
and ask “How far did they come?”
(Displacement), or “How fast did they stop?”
(Acceleration). The common question is “How
fast were they going when they hit?” (Velocity)
DISPLACEMENT is the peak to peak distance a
part is moving measured in “mils.” One mil
equals one thousandth of an inch (.001"). When
measuring in mils, the operating speed must be
known to establish a vibration condition limit.
(Example: a cooling tower fan operating at 175
RPM vibrating at 10 mils may be considered in
good condition. An electric motor operating at
1750 and vibrating at 10 mils typically requires
immediate attention.)
ACCELERATION - is useful for detecting the
deterioration and defects or rolling element
bearings and gears. An acceptable level for
most machines is less than 0.5 g’s. If the level is
higher, the bearing may be defective and should
be analyzed. An acceptable level of g’s can be
established by comparing similar machines and
by studying vibration trends.
Table 1: Comparison of Velocity, Displacement and Acceleration
SPEED
RPM
(cpm X 60)
DISPLACEMENT
MILS
(Peak to Peak)
VELOCITY
IN/SEC
(Peak)
ACCELERATIO
N
G’s
(Peak)
175 21.9 0.2 0.00945
1750 2.19 0.2 0.0945
17,500 0.219 0.2 0.945
175,000 0.0219 0.2 9.45
