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DISCONTINUED, We recommend DT-311D as a replacement

Range: 40-12,500 RPM/FPM
Type: Xenon
The Check-Line DT-721 Digital Stroboscope is a highly stable, industrial-quality instrument for non-contact RPM measurement as well as for inspection and observation of moving parts by freezing or slowing down the action.

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


  • Highly accurate speed control with drift-free operation
  • Accepts input from sensor for external flash triggering
  • Easy-to-use controls with bright LED display
  • Phase shift adjustment permits movement of objects to desired position for convenient observation
  • Instant double (2x) and half-rate (÷2) flash selection
  • Extremely lightweight and rugged


Flash Range40.0 - 12,500 FPM
Accuracy± 0.02% of reading
Resolution(0.1) 40.0 - 4,999.9
(0.2) 5,000.0 - 7,999.8
(0.5) 8,000.0 - 9,999.5
(1.0) 10,000.0 - 12,500.0
Display5-Digit LED, 8 mm high
Flash TubeXenon, 10 watt
Tube Life100 million flashes
Flash Duration10 - 15 µs
Signal OutputNPN Open Collector, 24 VDC max.
Phase Shift0 - 359° (Internal Mode)
Operating Temperature32 to 105° F (0 to 40° C)
Weight1.50 lbs. (680 g)
Warranty1 year

External Trigger Input Signal

A) 12 - 24 V DC through a 3-wire NPN sensor (requires external power supply)
B) 12 V DC through a 2-wire proximity sensor (Leakage Current 1 mA max. Load current 8 mA min.)
B) Switch or Relay Contact

Stoboscope Accessories

Related Products

DT-TRI Mini Tripod for Tachometers and Stroboscopes
Click image for more info
Mini Tripod for Tachometers and Stroboscopes
- Extendable legs reach 7" in height (5" when retracted)



Complete Kit

Optional Complete Kit is offered which also includes a carrying case and spare flash tube at minimal additional cost.


Buy Now

Item Description Price
Spare Flashtube for DT-725 and DT-721
In stock
1 Week Lead Time (Estimated)
2-3 Week Lead Time (Estimated)
Lead Time Varies, Please contact us for availability.