| CAUTION Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. |
This Vaisala Forward Scatter Sensor is classified as a Class 1M optical device in accordance with International Standard IEC/EN 60825‑1:2014. It complies with 21 CFR 1040.10 and 1040.11 except for the deviations pursuant to the Laser Notice No. 56.
The following table shows the characteristics of laser radiation emitted from the protective housing during the performance of operation and preventive maintenance procedures.
| Property | Value |
|---|---|
| Laser wavelength | 850 nm |
| Average power through 7-mm aperture in the plane of the laser aperture | < 0.75 mW |
| Beam divergence (horizontal) | 6° |
| Beam divergence (vertical) | N/A |
| Pulse duration | 1.6 µs |
| Repetition rate | 50 kHz |
The device incorporates a Class 3R laser with the following characteristics.
| Property | Value |
|---|---|
| Laser wavelength | 850 nm |
| Average power through 7-mm aperture in the plane of the laser aperture | < 4.18 mW |
| Beam divergence | 6° |
The measurement unit is equipped with the following labels:
The following figure shows the laser aperture and direction from the transmitter module.
- 1
- Laser aperture
- 2
- Laser radiation direction
Take the following precautions during service and maintenance:
| WARNING Do not look directly into the transmitter with magnifying optics (such as glasses, binoculars, and telescopes). |
| WARNING Do not remove the transmitter from its normal position without first switching off both the AC (mains) line and the battery power. |
| WARNING When operating the forward scatter sensor, do not look at the transmitter of the forward scatter sensor from the beam direction. |
| WARNING Only qualified maintenance personnel may perform maintenance procedures. Make sure unauthorized persons cannot access the work area during service operations. |
|
A hardware degrade may increase transmitter laser optical power past eye safety limits. FD70 monitors laser current for abnormally rapid changes caused by such hardware faults and alerts the user of a possible eye safety risk. Before starting any maintenance actions, make sure that the power is switched off. |