Vaisala CL51 Technical data

www.vaisala.com

CL51 Ceilometer for High-Range Cloud Height Detection

The Vaisala Ceilometer CL51 is designed to measure high-range cirrus cloud heights without surpassing the low and middle layer clouds, or vertical visibility in harsh conditions.

The CL51 employs a pulsed diode laser LIDAR (Light Detection And Ranging) technology, where short, powerful laser pulses are sent out in a vertical or near-vertical direction. The reection of light (backscatter) caused by clouds, precipitation or other obscuration is analyzed and used to determine the cloud base height.

Measurement from the ground level

The enhanced single lens technology applied in the CL51 ensures excellent performance starting at a height of virtually zero. The signal is strong and stable over the whole measurement range.

The CL51 is able to detect three cloud layers simultaneously. If the cloud base is obscured due to precipitation or ground-based fog, the CL51 reports Vertical Visibility. The CL51 is able to provide the backscatter prole over the full measurement range. This information provides a possibility for an advanced boundary layer and atmospheric analysis.

Designed for harsh weather

The CL51 has a shield with a blower and heater, which allows steady operation in precipitation and under extreme temperatures. Reliable solar protection is ensured by optical lters. A tiltable shield further protects the instrument

from precipitation and specular reection from ice crystals. The tilt angle measurement and correction is automatic.

Self-diagnostics

In addition to cloud height data, the fully automatic CL51 outputs messages with information on the instrument status. The information is based on comprehensive selfdiagnostic routines. In case of a malfunction the diagnostics help the user to identify the failed module.

Maintenance

Periodic maintenance of the CL51 is normally limited to window cleaning. There is no need for adjustments in the eld. The automatic window blower with heater improves performance by keeping the window clean and dry. In cold conditions heating prevents frost generation on the window. Any malfunction is automatically reported in the data and status messages.

Features/Beneﬁts

Cloud reporting range up to

▪

13 km (43,000 feet)

Second-generation, advanced

▪

single-lens optics with excellent performance also at low altitudes

Modular design for easy

▪

installation and maintenance

Reliable operation in all

▪

weather: unsurpassed performance in precipitation

Detection of Cirrus clouds

▪

CL51

Backscatter proﬁling over full

▪

range up to 15 km

Field-proven, fully automatic

▪

24/7 operation in all weather conditions

Extensive self-diagnostics with

▪

fault analysis

Based on robust and

▪

aordable laser diode technology

Latest technology from the

▪

world leading manufacturer

- installed base over 5,000 Ceilometers worldwide

Technical data

Performance

Cloud reporting range 0 ... 13 km (0 ... 43,000 ft.) Backscatter proﬁling range 0 ... 15 km (0 ... 49,200 ft.) Reporting cycle programmable 6 ... 120 s,

or polling Reporting resolution 10 m /33ft, units selectable Distance measurement accuracy

against a hard target greater of ±1% or ±5 m Laser InGaAs diode, 910 nm Eye safety Class 1M IEC/EN 60825-1

Electrical

Power (* 100/115/230 VAC

±10 %, 50 ... 60 Hz

max. 310 W incl. heating

Interfaces

Data RS232/RS485/Modem

Maintenance RS232

Bits per second

RS232/RS485 300 ... 115,200 Modem V.21, V.22, V.22bis 300 ... 2400

Backup battery Internal, 2Ah

Data messages

Cloud hits (up to 3 layers) and status information Cloud hits, status and backscatter proﬁle Emulation of CL31 and LD-40 Sky Condition (optional)

Environmental

Temperature range -55 ... +60 °C (-67 ... +140 °F) Humidity 0 ... 100 %RH Wind 55 m/s Housing classiﬁcation IP65 Vibration Lloyds Register/IEC 60068-2-6 EMC IEC/EN 61326 Electrical safety IEC/EN 60950

Accessories and options (*

Cable termination box Termbox-1200 with extra transient protection PC maintenance cable QMZ101 Shock absorbing mounting pad CT35022 for ship installations Modem module DMX501 Attachment mechanics for radio modem antenna CL51RADIOKIT Graphical User Interface for Ceilometers CL-VIEW Bird deterrent device CL51BIRDKIT

(* Please specify power and optional accessories when ordering.

Mechanical

Dimensions

Total 1531 x 364 x 354 mm

Measurement unit 834 x 266 x 264 mm Weight

Total 46 kg

Measurement unit 18.6 kg Tilt positions Vertical or 12° tilted Automatic window blower/heater Radiation shield and pedestal Service access through a door Optical ﬁlters for protection against direct sunlight

For more information, visit www.vaisala.com or contact us at sales@vaisala.com

This material is subject to copyright protection, with all copyrights retained by Vaisala and its individual partners. All rights reserved. Any logos and/or product names are trademarks of Vaisala or its individual partners. The reproduction, transfer, distribution or storage of information contained in this brochure in any form without the prior written consent of Vaisala is strictly prohibited. All speciﬁcations — technical included — are subject to change without notice.