Detail LUTRON DT-2234BL Laser Photo Tachometer :

• Laser light detecting source, long measuring range up to 2 meters, it is useful in the RPM measurement application where the machine would be a risk to the operator or close access is difficult or not possible
• Wide measuring range from 1 to 100,000 RPM, 0.1 RPM resolution for the measured value <1000 RPM
• Microprocessor based circuit, cristal time base, high precision with 005% accuracy
• High visible LCD display gives RPM reading exactly with no guessing or errors and saves battery energy
• Memory with recall function, the last value, max., value, min. value will be stored into the memory automatically
• The use of durable, long kasting components, including a strong, light weight ABS plastic housing, assures almost maintenance free performance for many years.

General Specifications:

• Display :  5digits, 10 mm (0.4 inch) LCD, with function annunciation
• Measurement and range : 10 to 99,999 RPM
• Resolution : 0.1 RPM (<1,000 RPM) 1 RPM (1,000 RPM)
• Accuracy : ± (0.05% + 1 digit)
• Detecting Distance : 50-2,000 mm typically ( Spec. of detecting distance are that under the size of
  reflecting tape is 10 mm square & the measuring RPM
  value is 1,800 PPM. The max. detecting distance may
  change under different environment, different reflecting tape or the measuring RPM beyond 1800 PRM.)
• Laser light source :
  – Less than 1 mW
  – Class 2 laser red diode
  Wave length is 645 nm approximately
• Time base : Quartz crystal, 4.194 MHz
• Circuit : Exclusive one-chip of microcomputer LSI circuit
• Operating temperature : 0^◦C to 50^◦C ( 32^◦F to 122^◦F ).
• Operating humidity : less than 80% RH
• Memory : Last/Max./Min…. value
• Battery : 4 x 1.5V AA (UM-3) battery
• Power consumption : Approx. DC 20 mA
• Size : 190x72x37 mm
• Weight : 250g /0.55 LB (including battery)