Checkline DT-725 User Manual

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TABLE OF CONTENTS

1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

02

2.0 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

02

2.1 Controls

2.2 Kit Option

3.0 Battery Usage (DT-725 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

03

3.1 Battery Charging

3.2 Battery Replacement

4.0 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

04

4.1 Internal Triggering

4.2 External Triggering

4.3 Synchronous Output Signal

4.4 Using A Tripod

5.0 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

06

6.0 True RPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

06

7.0 Flash Tube Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

07

8.0 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

08

9.0 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

WARNING

1. Do not look at the emitted light for long periods of
time, it can be harmful to the eyes.

2. Do not disassemble or repair the unit while in
operation.

3. Do not operate or store the instrument in the
following places: explosive areas, areas near
water, oil, dust or chemicals, or areas where
the temperature is above 104°F

(40 °C).

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8.0 SPECIFICATIONS

Flashing Range 40 – 12,500 FPM (Flashes Per Minute)

Accuracy ±0.02% of reading

Resolution 0.1 , 40.0 – 4,999.9 FPM

0.2 , 5,000.0 – 7,999.8 FPM

0.5 , 8,000.0 – 9,999.5 FPM

1.0 , 10,000.0 – 12,500.0 FPM

Display 5-Digit LED, 0.3" (8mm) height

Rate Divide by 2, Multiply by 2

Update Time Ext. mode: varies with flashing rate

Operating Time 1 hour when fully charged (Model DT-725)

Continuous (Model DT-721)

Flash Tube/Power Live Xenon, 10 W, 100 million flashes

Flash Duration 10 – 15 μs

Signal Output NPN Open Collector (24 VDC max., 50 mA)

150 μs typical

Phase Shift Internal mode only by using the “+” and “–” switches

Ext. Trigger a) 12-24 VDC thru a 3-wire NPN output sensor

(requires external power supply)

Input Signal b) 12 VDC thru a 2-wire proximity sensor (leakage

current 1 mA max.,Load current 8 mA min.)

c) Switch or Relay contact

Operating Temp. 32°–104° F (0 – 40° C)

Dimensions 9" L x 4.3" W x 8.5" H (228.6 x 109.2 x 216.9mm)

(Height includes handle)

Weight DT-725 2.75 lbs (1.25 Kgs)

DT-721 1.5 lbs. (0.7 Kg)

4.3" (109.2mm)

4.3" (109.2mm)9" (228.6mm)

8.5"

(228.6mm)

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1.0 INTRODUCTION

The Check•Line®DT-721(AC-powered) and DT725 (battery powered) Digital
Stroboscopes are highly stable, industrial-quality instruments for non-contact
RPM measurement as well as for inspecting and observing moving parts
by “freezing” or “slowing down” the action.

2.0 OVERVIEW

2.1 Control Panel

Setter: The setter changes the flash
rate. Tune CW to increase the rate,
turn CCW to decrease the ratee.

x2 Switch; Pressing “x2” will double and
display the flashing rate.

1/2 Switch: Pressing the “1/2” will divide

flashing rate by two and display it.

Plus (+) Switch: When object appears to

be standing still, pressing “+” will give the
illusion that the object is moving towards the
opposite direction of rotation. This action
increases the rate slightly (phase shift) and is
used to place the object in desired position.

Minus (–) Switch: When object appears to
be standing still, pressing “–” will give the
illusion that the object is moving towards the
rotating direction. This action decreases the
rate slightly (phase shif) and is used for the
same reason as above.

Input and Output Connectors:

Phonejack (3.5 mm)
Tip: Signal
Sleeve: GND

Power switch with lock option
Power cord (DT-721 only, not shown)

2.2 Kit Option

A “Kit” option is offered which also
includes a carrying case and spare
flash tube at minimal additional cost.

Setter

Input &

Output

Connectors

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7.0 FLASH TUBE REPLACEMENT

When FPM reading is displayed but unit is not flashing, the flash tube may need
to be replaced.The procedure is as follows:

1. Unplug line cord from power line (DT-721). Turn power switch OFF.

IMPORTANT: Wait a few minutes until stroboscope is cool before replacing
flash tube.

2. Remove protective window by removing the
four (4) screws on the face of the instrument.

3. Use a rag and pull the tube out of its socket
by rocking it slightly back and forth.

IMPORTANT: Do not use bare hands to remove
the tube, it may break and cause injury.

4. Insert new tube using the technique mentioned
above. Make sure that the tube is placed vertically

in the socket (see diagram below) otherwise it will
touch the reflector. Tube should be set symetrically
within the neck of the reflector.

5. Replace the protective window.