Sentry ST 723 User manual

Instruction
Manual
MODEL:ST 723
Contact / Non-Contact Tachometer
RoHS
COM P L IAN T
REACH
(SVHC)

Instruction
Manual
Contact / Non-Contact
Tachometer
RoHS
COM P L IAN T
REACH
(SVHC)

Table Content

1
1. Product Introduction
Thank you for purchasing the Digital Tachometer.
The Digital Tachometer is Contact and Non-Contact
RPM (revolutions per minute) measuring instruments.
Features include a 5 digits LCD, scan/hold function
and auto power off (30 seconds). To measure, point
the Laser spot or bring the contact probe to the object.
Press the measuring trigger and hold on till the reading
is stable and end of shot.
1-1 Features
Measurement type : Rotation Speed (RPM)、
Non-contact RPM measurements up to 100cm
away from target.
Laser sighting.
Contact measurements can be made with included
contact adapters.
5 digital microprocessor-controlled LCD display.
40 reading memories: 10 selectable MAX
10 selectable AVG measurements and 10 selectable
DATA measurements.
Ultra low power consumption in shutdown mode.
Total revolutions (REV)、Surface Speed (I/M、
M/M、Y/M、F/M) and Length(M、YD、FT).
measurements, 10 selectable MIN measurements,

Use of controls or adjustments or performance of
procedures other than those specified here may
result in hazardous radiation exposure.
Do not look at the laser beam coming out of the lens
or view directly with optical instruments - eye damage
can result.
1-3 Warnings!
1-2 Application
Gear Boxes
Engines
Motors
Pumps
Compressors
Centrifuges
Couplings
Fans
Shafts
Grinders
Pulleys
Length Measurement
2
You may receive harmful laser radiation exposure if
you do not adhere to the warnings listed below:

Read the following safety information carefully before
attempting to operate or service the meter. Only qualified
personnel should perform repairs or servicing not covered
in this manual.
2. Safety Information
Do not look directly into the laser beam. Permanent
eye damage may result.
Do not point the laser at anyone's eyes.
Use caution when operating the laser around
reflective surfaces.
2-1 Laser Warning Note!
Use extreme caution when operating the laser sighting.
Never point the laser beam at a person.
Do not attempt to open the tachometer. There are no
user serviceable parts.
Keep out of the reach of all children.
3
Refer to the inside back cover for product warning label.

This product contains a Class 2 laser; use caution
when operating this device with the laser on.
Do not submerge the unit in water.
Do not use an extension shaft as the adapters may
come off of the shaft and cause damage or injury.
If operating arrangements are used or procedures
carried out other than those described here in these
instructions, this can lead to dangerous exposure to
radiation.
2-2 Cautions!
2-3 Symbols
Dangerous, refer to this manual before using the meter.
CE Certification.
This instrument conforms to the following standards:
EN61326:Electrical equipment for measurement, control
and laboratory use.
IEC61000-4-2:Electrostatic discharge immunity test.
IEC61000-4-3:Radiated, radio-frequency, electromagnetic
field immunity test.
4

5
IEC61000-4-8:Power frequency magnetic field immunity
test.
IEC60825-1:Safety.
Tests were conducted using a frequency range of 80 -
1000MHz with theinstrument in three orientations. The
average error for the three orientationsis ±0.5℃ (±0.1℉)
at 3V/m throughout the spectrum. However, between 781-
1000MHz at 3V/m, the instrument may not meet its stated
accuracy.
RoHS
Restrict to use of six substances within electrical
and electronic equipment (EEE), thereby contributing
to the protection of human health and the environment.
The device may not be disposed of with the trash.
It promotes the re-use recycling and other forms
of recovery of used materials and components, and
to improve the environmental performance of all
operators (manufacturers, traders and treatment
facilities) involved in the life cycle of products.
Dispose of the product appropriately in accordance
with the regulations in force in your country.
REACH
The device of used materials content no following
substances that list of proposed REACH substances
of very high concern.

3. Specification
6.0 – 5999.9 RPM : ±0.01% and ±1digit
Surface Speed,Length 0.5% and±1digit
6000.0 – 99999RPM : ±0.05% and
±1digit
6
9V Battery, Instruction manual,
Cone adapter,Funnel adapter,
Contact adapter, Master Wheel (10cm),
Reflective tape 15x525mm (0.59"x20.67"),
Carrying Case
Range of Non-Contact 6.0 - 99,999 RPM(rev/min)
Range of Contact 6.0 - 25,000 RPM(rev/min)
Range of
Surface Speed
0.6 - 2,500.0 M/M (m/min)
0.7 - 2734.0 Y/M (yard/min)
23.6 - 98425 I/M (inch/min)
2.0 - 8202.1F/M(fee/min)
0.1-9999.9 M(m) 0.1-10936 YD (yard)
0.3-32808 FT (feet)
Total number of revolutions 1 - 99999(REV)
Accuracy
Lengh(cantact)
Detection Laser Diode
Resolution 6.0 - 9999.9 RPM : 0.1RPM
10000 - 99999 RPM : 1RPM
Response Time 1 second
Operating Temp. 0 to50
℃ (32 to 122 ), 10 to 90%RH
℉
Auto power off Automatically after approx. 30s.
Max/Min/Avg Yes
Memory 40 points
Battery Type 9V(006P, IEC6F22, NEDA1604)
Dimensions 182x49x29mm (7.17"x1.93"x1.14")
Include Contact Adapters
Weight 95g(3.35 oz) Approx (without battery),
Contact adapter: 50g (1.76 oz)
Standard Accessories

4. Operation
4-1 Quick Start
7
A. Flip open the battery compartment cover and install a
9V Battery.
B. Non-Contact: Stick the self- adhesive reflective tape
on the object whose rotational speed
is to be measured. The reflective tape
should be stocked as close to the
outer edge of the object to be measured
as possible.
Contact: Attach the contact adapter to the tachometer
(Do not over tighten!). Select the adapter
included and slides it onto the shaft of the
contact adapter. Align the adapter with the
alignment pin on the shaft of the contact
adapter.
C. Hold the tachometer in your hand.
D. Press the MEAS button. Point the laser spot at the object
(the reflective tape) or bring the contact probe to the
object. Then read the measurement on the LCD display.

4-2 Unit Diagram
8
1
2
3
4
5
6
7
8
9
10
11
1 Laser beam outlet: Used for Non-contact RPM
measurements.
2 Display section: Displays measurements.
3 Mbutton: Data Storage and Recall Data.
4 Unit button: Contact, Non-Contact and the relative
measurements mode switch.
5 MEAS button: Turns the tachometer on and records
measurements.
6 Battery and cover.
7 Laser warning and certification label.
8 Contact adapter: Used to make all contact
measurements.
9 Cone adapter.
10 Funnel adapter.
11 Master Wheel (10cm cir).

4-3 Display
a Main display: 5 digit LCD displays measurement
readings.
b Scan: Press the measuring button, the data will update
and "SCAN" will show.
c Hold: Release the measuring button, the data will freeze
and "Hold" will appear.
d Unit display: Displays measuring units.
e Low battery display: When the battery current is weak,
will show.
f Max / Min / Avg display: Displays minimum, maximum
and average value.
g Data: Displays the number of data storage.
a b
fg
c d e
9

4-4 Function Descriptions
10
In Scan mode, the current measurement is displayed
on the main display. The main display will hold the last
values until the tachometer automatically turns off.
Memory mode:
The tachometer can store or recall 10 selectable
MAX measurements, 10 selectable MIN
measurements, 10 selectable AVG measurements
and 10 selectable DATA measurements.
To store a measurement:
Press the MEAS button until the reading displayed
on the LCD display. Observe the reading and press
the M button to record. The maximum, minimum,
average and data during one shot measurement
will be stored into a memory set. Then the Data
number will increase by one.
To recall the stored data from memory:
Use the M button to scroll and view the stored data point.
a) See the flow chart 1 for a brief presentation of how
to recall the stored data sequentially.
b) See flow chart 2 for a brief presentation of how to
quick access or leap the data set to the next.
Stored data points will appear in the main display. Empty
memory locations will read "-----". Maximum, minimum
and average data will appear in the RPM, rPm, I/M,
M/M, Y/M and F/M display with MAX/MIN/AVG symbol.

Chart 1
Press the “M” button once to next Storage
……………
Data0 Min Data0Max Data0 Avg Data0
Data1 Min Data1Max Data1 Avg Data1
Data9 Min Data9Max Data9 Avg Data9
Data2 Min Data2Max Data2 Avg Data2
11

Chart 2
Press the “M” button and hold for approx.
3 sec to leap to next Data Set
……………
Data0 Min Data0Max Data0 Avg Data0
Data1 Min Data1Max Data1 Avg Data1
Data9 Min Data9Max Data9 Avg Data9
Data2 Min Data2Max Data2 Avg Data2
12

Contact and Non-Contact Measurement Mode Switch:
The functions are separated into two group of
measurement. One is the rate measurement which is
shown on the left side of the following flow chart.
The other is the revolution and length measurements
which are shown on the right side of the following flow
chart.
The user can press the "U" button once to change from
RPM, rPm…. to the next sequentially.
Press the "U" button and hold for approx. 3 sec to leap
to next group.
13

RPM
rPm
I/M
M/M
Y/M
F/M
REV
M
YD
FT
Press for 3 sec.
U
U
U
14

RPM : Non-Contact revolutions per minute
measurements.
rPm : Contact revolutions per minute measurements.
I / M : Contact Inch per minute measurements.
M/M : Contact Meter per minute measurements.
Y/M : Contact Yard per minute measurements.
F/M : Contact Feet per minute measurements.
REV : Revolution measurements.
M : Length (Using the master 10cm circumference
wheel.) measurements in the unit of meter.
Y D : Length (Using the master 10cm circumference
wheel.) measurements in the unit of yard.
F T : Length (Using the master 10cm circumference
wheel.) measurements in the unit of feet.
15
Non-contact measurement should avoid the blinking
light source in the front or around the target, such as
the fluorescent lamp which will cause the wrong reading.
★Remark

Cleaning the lens:
Blow loose particles from the lens using clean
compressed air. Gently brush remaining debris away
with a camel's hair brush. Carefully wipe the surface
with a cotton swab moistened with water.
NOTE:
DO NOT use solvents to clean the lens.
Clean the housing:
Use soap and water on a damp sponge or soft cloth.
NOTE:
Be careful not to allow any liquids or moisture to get
inside the tachometer.
5. Maintenance
16