LWS Leaf-Wetness Sensor
Sensitive yet Durable
Compatible with most Campbell Scientific data loggers
weather applications supported water applications supported energy applications supported gas flux and turbulence applications supported infrastructure applications supported soil applications supported

Overview

The LWS, manufactured by METER Environment, can detect small amounts of water or ice on the sensor surface for leaf wetness applications. Because the LWS measures the dielectric constant of the sensor’s upper surface, it can detect the presence of water or ice anywhere on the sensor’s surface. 

The LWS is designed to be deployed either in the canopy or on a weather station mast. Two holes in the non-sensing portion of the sensor body are provided for attaching the sensor to a pole or branch via twist ties or with 4-40 bolts.

Note: The LWS was previously ordered as the LWS-L.

Benefits and Features

  • Imitates characteristics of a leaf
  • Does not require painting or calibration of individual sensors
  • Detects trace amounts of water or ice on the leaf surface

Images


Specifications

Measurement Description Dry, frosted, wet
Signal Type/Output Analog voltage
Measurement Time 10 ms
Power 2.5 Vdc @ 2 mA to 5 Vdc @ 7 mA
Output 250 to 1500 mV (millivolt reading relates to moisture state)
Operating Temperature Range -40° to +60°C
Life Expectancy 2+ years (continuous use)
Painting Does not require painting.
Dimensions 12.0 x 5.8 x 0.8 cm (4.7 x 2.3 x 0.3 in.)
Weight 0.14 kg (5 oz) with 4.57 m (15 ft) cable

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Data Loggers

Compatible Note
CR1000 (retired)
CR1000X
CR300
CR3000 (retired)
CR310
CR350
CR6
CR800 (retired)
CR850 (retired)

Additional Compatibility Information

Installation

The LWS is designed to be deployed either in the canopy or on a weather station mast. Two holes in the non-sensing portion of the sensor body are provided for attaching the sensor to a pole or branch via twist ties or with 4-40 bolts.

Related Documents


FAQs for

Number of FAQs related to LWS: 8

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    • The ability of the LWS to detect water on its surface is not limited by the size of the water droplets, as it can be with a 237-L. 
    • The LWS is ready to install for most applications, whereas the 237-L requires further preparation before installation.
    • The LWS can detect the presence of ice and differentiate ice from water. In contrast, when ice forms on the 237-L, the sensor’s output is no different from that of a dry sensor.
  1. Both leaf wetness sensors are compatible with all Campbell Scientific data loggers. However, the 237-L is often used in large legacy networks that rely on the 237-L for data continuity. The 237-L does require painting and field calibration, whereas the LWS does not.

  2. Most Campbell Scientific sensors are available as an –L, which indicates a user-specified cable length. If a sensor is listed as an –LX model (where “X” is some other character), that sensor’s cable has a user-specified length, but it terminates with a specific connector for a unique system:

    • An –LC model has a user-specified cable length for connection to an ET107, CS110, or retired Metdata1.
    • An –LQ model has a user-specified cable length for connection to a RAWS-P weather station.

    If a sensor does not have an –L or other –LX designation after the main model number, the sensor has a set cable length. The cable length is listed at the end of the Description field in the product’s Ordering information. For example, the 034B-ET model has a description of “Met One Wind Set for ET Station, 67 inch Cable.” Products with a set cable length terminate, as a default, with pigtails.

    If a cable terminates with a special connector for a unique system, the end of the model number designates which system. For example, the 034B-ET model designates the sensor as a 034B for an ET107 system.

    • –ET models terminate with the connector for an ET107 weather station.
    • –ETM models terminate with the connector for an ET107 weather station, but they also include a special system mounting, which is often convenient when purchasing a replacement part.
    • –QD models terminate with the connector for a RAWS-F Quick Deployment Station.
    • –PW models terminate with the connector for a PWENC or pre-wired system.
  3. Not every sensor has different cable termination options. The options available for a particular sensor can be checked by looking in two places in the Ordering information area of the sensor product page:

    • Model number
    • Cable Termination Options list

    If a sensor is offered in an –ET, –ETM, –LC, –LQ, or –QD version, that option’s availability is reflected in the sensor model number. For example, the 034B is offered as the 034B-ET, 034B-ETM, 034B-LC, 034B-LQ, and 034B-QD.

    All of the other cable termination options, if available, are listed on the Ordering information area of the sensor product page under “Cable Termination Options.” For example, the 034B-L Wind Set is offered with the –CWS, –PT, and –PW options, as shown in the Ordering information area of the 034B-L product page.

    Note: As newer products are added to our inventory, typically, we will list multiple cable termination options under a single sensor model rather than creating multiple model numbers. For example, the HC2S3-L has a –C cable termination option for connecting it to a CS110 instead of offering an HC2S3-LC model. 

  4. Many Campbell Scientific sensors are available with different cable termination options. These options include the following:

    • The –PT (–PT w/Tinned Wires) option is the default option and does not display on the product line as the other options do. The cable terminates in pigtails that connect directly to a data logger.
    • In the –C (–C w/ET/CS110 Connector) option, the cable terminates in a connector that attaches to a CS110 Electric Field Meter or an ET-series weather station.
    • In the –CWS (–CWS w/CWS900 Connector) option, the cable terminates in a connector that attaches to a CWS900-series interface. Connection to a CWS900-series interface allows the sensor to be used in a wireless sensor network.
    • In the –PW (–PW w/Pre-Wire Connector) option, the cable terminates in a connector that attaches to a prewired enclosure.
    • In the –RQ (–RQ w/RAWS Connector) option, the cable terminates in a connector that attaches to a RAWS-P Permanent Remote Automated Weather Station.

    Note: The availability of cable termination options varies by sensor. For example, sensors may have none, two, or several options to choose from. If a desired option is not listed for a specific sensor, contact Campbell Scientific for assistance.

  5. To incorporate a sensor that is compatible with wireless sensor interfaces into a wireless network, a CWS900-series wireless sensor interface is needed, as well as an A205 CWS-to-PC interface to configure it.