Is it possible to measure to a moving target?
The Dimetix sensors are able to measure on moving targets. Thereby the maximal possible object speed depends on the following factors:
- Measuring condition (light conditions, ambient light)
- Object- / Measuring surface condition
- Sensor specification measuring speed / rate (see Products)
Generally with higher measuring rates the maximal object speed will be higher as well. Realize that the measured distance is averaged over the measuring time of one measurement.
How is the measuring rate influenced?
The measuring rate of the sensors is influenced by different factors. Essentially the signal level of the reflected laser light has an important influence on the measuring rate. On a bright measuring surface (e.g. white) with good reflectivity, a measurement takes less time than on a dark surface (eg. black) with low reflectivity.
The following factors can influence the measuring rate / measuring speed in a positive manner:
- Condition of the measuring surface (e.g. mat, smooth)
- No / little background light (e.g. sunlight, spotlight)
- Reduction of the measuring distances
- Configuration of the sensor
What is the measuring accuracy?
The measuring accuracy of the Dimetix sensors is specified with a statistical confidential level of 95.4% (corresponds to ISO 1938-2015). This is equivalent to ±2σ or 2 times the standard deviation σ (see the figure).
The following distance errors are considered in this measuring accuracy as well:
- Distance error due to temperature influence (Sensor temperature)
- Linearity error
Realize that the sensors do not compensate the humidity, the air pressure or the air temperature. If the environment conditions differ from 60% relative humidity, 953mbar air pressure or 20°C air temperature, the accuracy can be influenced if the measuring distances is longer than 150m. The influence of these environment conditions is described in H. Kahmen & W. Faig: “Surveying”, (1988).
How long could be the RS-232 data cable?
The RS-232 interface is not designed for long data cables (no differential signals). The maximal cable length is mainly defined by the data rates of the RS-232 interface. See the following guidelines:
- 9’600 Baud → up to 152m
- 19’200 Baud → up to 15m
- 115’200 Baud → up to 2m
The cable length is also influenced positive or negative by other factors:
- Quality of the cable (Shielding, wire resistance, etc.)
- Environmental conditions (Disturbance sources like motors, etc.)
Does dust influence the measuring process?
The influence of dust on distance measurements depends on the density of dust. If the main part of the laser beam is reflected by dust particle, the distance measurement will be influenced in a negative way (measurement errors). However, such conditions can only be found in extreme dusty environments like cement silos.
On what kind of targets can be measured?
All opaque targets can be measured if they do not have highly reflective surfaces. Reliable measurements on transparent targets are not possible.
Is it possible to measure through glass?
It is not recommended to measure through glass, since there is a signal lost and reflections on the glass may have a negative impact on the accuracy.
However, if a glass is the only option for a specific application, check the following points:
- Use coated glass to reduce the reflections and signal losses
- Install the glass with an angle to the front of the sensor of 5° min.
- Keep the glass clean all the time
Is the Laser Light eye safe?
The Dimetix sensors belong to laser class 2. Sensors of this laser class have visible laser light and a laser power less than 1mW (<1mW).
Realize that in normal case the bright light of a class II laser beam into your eyes will cause a normal reaction to look away or close the eyes. This response is expected to protect you from Class II Laser damage to the eyes.
If class II laser beams are directly viewed for a long period of time damage to the eyes could result. Avoid looking into a class II laser beam or pointing into another person’s eyes. Avoid viewing class II laser beams with telescopic devices.