Details

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A laser type oil film detector, developed to detect a film of oil on water surfaces in drainage ditches, pits, oil water separating tanks, purification plant water inlets, etc., and generate an alarm. Detection performance for which the conventional detector (LMD-2000) had a reputation is greatly improved as well as maintainability is enhanced Utilize the LMD-3000 for early response to oil leaks and prevention of oil outflow accidents which threaten river and marine environments.
 

Salient features

1. Stable detection performance (no false alarms)

Conventional method of emitting laser beams to water surfaces and receiving reflected lights uses a spotlight as the light source. In this method, ripples and waves can cause the emitted laser beams to reflect irregularly, disabling the reflected lights to be received. Thus it is not practical in cases where the water level fluctuates largely or where ripples and waves form due to high flow. (Fig. 1)

In contrast, the LMD-3000 laser emission method linearly emits a laser beam and rotates it by 360 degrees around one end of the line. On an actual water surface, an entire circular area with a diameter of 150 to 500 mm is continuously scanned: a 150 mm diameter area in case of 1 m above the surface, a 500 mm diameter area in case of 3 m above the surface. This method allows some points within the circular area to necessarily reflect the applied beam back toward the MLD-3000 light receiver even if there are water flows or ripples, implementing stable light detection (Fig. 2).

This feature enables reflected light detection without adjustments in locations with water level fluctuations as long as the distance between the detector and the water surface is between 30 cm and 4 m. The LMD-3000 can support water level fluctuations up to 6 m on still water surfaces. It uses a combination of an optical filter, electronic filter, and software to prevent malfunction from being caused by disturbance light such as sunlight or fluorescent light. False alarms caused by floating materials with high reflectance such as aluminum foil and plastic film can be avoided by increasing the continuous detection time*.

*What is continuous detection time?

Continuous detection time is time during which the condition of the detection level of generating alarm has continued, being added to the detection criteria. The time is set according to the status of the flow rate and oil film in the detection location. It may be set between 1 and 999 sec. For example, if the time is set to 10 sec., it is judged that there is no oil when the oil flow under the detector is interrupted within 10 sec. On the contrary, when the oil continuously flows for 10 sec. or longer, it is judged that there is oil. In this way, setting an area (time) for Oil detector can avoid sensitive detection of small amounts of oil.

2. Variable settings of oil film width for alarm generation (area detection function)
Whether to generate an alarm can be determined according to the ratio (%) of an oil film on the monitored water surface (2 m or lower still water surface) Oil leak alarms are prevented from being generated by factors other than oil leak accidents (such as oil films staying on water, iron bacteria, insects, or fish).

3. Easy Installation
Conventional laser type oil film detector must have the optical axis set to be vertical to the water surface, requiring precise alignment of the optical axis during installation. The LMD-3000, by contrast, is structured to have its optical components emplaced in a free-hanging assembly in the case, so that the optical axis of the laser beam is constantly in the vertical direction even if the case inclines slightly, requiring no optical axis alignment during installation.

4. Easy Maintenance
Due to the non-contact system, the daily maintenance required is only wiping debris off the glass window at the bottom of the detector. In addition, laser-related design is drastically improved to extend the maintenance cycle to 4 years (twice the conventional one). Please Contact Us for laser-related consumables.

5. Easy-to-view Monitor
3.5-inch large-screen color LCD (with a touch panel) has been employed to exceedingly improve visibility and operability. Color graphic display enables the monitored state to be identified at a glance

6. Pressure-resistance and explosion-proofness supported (LMD-3000EX)
Available in Class 1 hazardous locations where an explosive atmosphere exists continuously or for a long period of time. The pressure-resistant and explosion-proof model of already commercially available LMD-3000 with its performance as is.
 

Specifications

LMD-3000 Specifications

Subject of detection	Oil on water surface or liquid on floor
Detection method	Surface-scanning laser/reflected light sensor
Water level fluctuation	0.3 to 4.0 m between surface and detector
Operating temperature	-10 to +50°C (Water surface should not freeze)
Structure	Sealed case applicable for outdoor use
Output signals	0 to 20 mA analog oil film detection signal, form A or form B relay contacts available for both oil film detection and system error
Alert conditions	1 to 999 sec. continuous detection, adjustable in 1 sec. increments
Display	4 to 20 mA light sensing level, 4 to 20 mA detection threshold
Power supply	AC 100-110 V , 50 or 60 Hz
Dimensions	185 mm diam. x 547mm H
Weight	Approx. 11 kg (excluding the installation stand)
Attached cable	5 m, 1.25 mm sq., 3-wire power cable, and 5 m, 0.5 mm sq., 8-wire shielded sheath signal cable

LMD-3000EX Specifications

Subject of detection	Oil on water surface or liquid on floor
Detection method	Surface-scanning laser/reflected light sensor
Water level fluctuation	0.3 to 4.0 m between surface and detector
Operating temperature	-10 to +50°C (Water surface should not freeze)
Structure	Explosion-proof construction,IP55
Output signals	4 to 20 mA analog oil film detection signal, 1C relay contacts available for both oil film detection and system error
Alert conditions	1 to 999 sec. continuous detection, adjustable in 1 sec. increments
Display	4 to 20 mA light sensing level, 4 to 20 mA detection threshold
Power supply	AC 100-110 V , 50 or 60 Hz
Dimensions	220 mm diam. x 595mm H
Weight	Approx. 28 kg (excluding the installation stand)
Attached cable	3-wire power cable, and 6-wire shielded sheath signal cable

System schematic

LMD-3000(Standerd model)

LMD-3000EX(Pressure/explosion-resistant model)