Laser LS8000-3 Mounting Distance, Laser Safety, Environmental Conditions, Ambient Temperature

LaserSpeed 8000-3 Instruction Handbook

Installing the System

Mounting Distance

When the material is within the depth of field, the gauge makes accurate measurements. Since the best signal comes from the center of the depth of field, the center is the source of the best measurements. This is because the two laser beams totally overlap at the center of the beam crossings and all of the laser power is used to form fringes.

At the edges of the depth of field, however, some beam-crossing areas overlap and some do not. The areas that overlap form fringes and thus yield useful Doppler signals; the areas that do not overlap do not form fringes; rather, they produce only noise with no Doppler signals. Any measurements made outside the depth of field may not be reliable.

Laser Safety

When mounting of the gauge, ensure that the laser beams are blocked by machinery or beam blocks when material is not present in the measurement area.

Environmental Conditions

Ambient Temperature

All LaserSpeed gauges have a built-in cooling system for applications in which ambient temperatures exceed 45ºC.

Cooling fluids can be routed through the gauge using the 1/8-inch NPT fittings (1/4" NPT on LS8000E and LS8000X) on the back of the gauge. Typical flow rates of 1.5 litres/minute for water and 50 liters/minute for air are sufficient.

There is minimal pressure drop through the gauge, so supply pressure can be very low.

Ensure that the water temperature is above the condensation temperature or dew point, to prevent condensation from collecting on the front window of the gauge. If water condenses on the optical window, the laser beams could be blocked, resulting in reduced performance or loss of function.

Coolant

In applications with coolants on the material, an air jet may be required to remove the coolant from the measurement area. Since the speed of the coolant is generally different from that of the material, erroneous measurements could result. When incorporating an air jet, be sure to blow the coolant from the measurement volume at 90° from the material’s motion. If the

Part No. 93463 / Drawing No. 0921-01561 Page 17 of 221 Revision A (Sep 2007)