Campbell Scientific 255-100 User Manual

255-100 Novalynx Analog

Output Evaporation Gauge

1/09

Copyright © 2009

Campbell Scientific, Inc.

Warranty and Assistance

The 255-100 NOVALYNX ANALOG OUTPUT EVAPORATION
GAUGE is warranted by CAMPBELL SCIENTIFIC, INC. to be free from

defects in materials and workmanship under normal use and service for twelve
(12) months from date of shipment unless specified otherwise. Batteries have
no warranty. CAMPBELL SCIENTIFIC, INC.'s obligation under this
warranty is limited to repairing or replacing (at CAMPBELL SCIENTIFIC,
INC.'s option) defective products. The customer shall assume all costs of
removing, reinstalling, and shipping defective products to CAMPBELL
SCIENTIFIC, INC. CAMPBELL SCIENTIFIC, INC. will return such
products by surface carrier prepaid. This warranty shall not apply to any
CAMPBELL SCIENTIFIC, INC. products which have been subjected to
modification, misuse, neglect, accidents of nature, or shipping damage. This
warranty is in lieu of all other warranties, expressed or implied, including
warranties of merchantability or fitness for a particular purpose. CAMPBELL
SCIENTIFIC, INC. is not liable for special, indirect, incidental, or
consequential damages.

Products may not be returned without prior authorization. The following
contact information is for US and International customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company
serves your country. To obtain a Returned Materials Authorization (RMA),
contact CAMPBELL SCIENTIFIC, INC., phone [phone]. After an
applications engineer determines the nature of the problem, an RMA number
will be issued. Please write this number clearly on the outside of the shipping
container. CAMPBELL SCIENTIFIC's shipping address is:

CAMPBELL SCIENTIFIC, INC.

RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

CAMPBELL SCIENTIFIC, INC. does not accept collect calls.

255-100 Table of Contents

PDF viewers note: These page numbers refer to the printed version of this document. Use
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1. General .........................................................................1

2. Specifications ..............................................................2

3. Installation....................................................................4

4. Wiring............................................................................ 4

5. Programming ...............................................................5

6. Calibration .................................................................... 7

7. Automatically Refilling the Evaporation Pan ............8

8. Recommended Solenoids........................................... 9

9. Storage Tank Size........................................................9

10. Installation and Maintenance.................................. 10

Figures

1. 255-100 Connected to 255-200 Using 255-100P/F....................................2

2. 255-100 Novalynx Analog Output Evaporation Gauge .............................2

3. 255-200 Novalynx Class A Evaporation Pan .............................................3

4. 255-100P/F Novalynx Stainless Steel Pipe and Fittings for

Evaporation Pan.......................................................................................3

5. 255-100 Schematic .....................................................................................4

6. Close-up of Terminal Strip on 255-100......................................................4

7. Determining the Multiplier and Offset for an Evaporation Gauge.............8

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255-100 Novalynx Analog Output Evaporation Gauge

1. General

Novalynx Corporation manufacturers the 255-100 Analog Output Evaporation
Gauge and the 255-200 Class A Evaporation Pan. The 255-100 consists of a
stilling well and potentiometer based shaft encoder. It is a low-power option
for reading the water level of an evaporation pan such as the 255-200.

The 255-100 consists of a chain-mounted float and counter weight that turns a
sprocket attached to a precision 1000 ohm potentiometer. When provided with
a precision excitation from the datalogger, the NovaLynx 255-100 Evaporation
Gauge produces a DC voltage that changes proportionally to the change in
water depth of the evaporation pan. The datalogger measures the voltage to
determine water level and, consequently, evaporation and rainfall. Using the
255-100P/F Steel Pipe & Fittings, the gauge may be installed outside of, but
hydraulically connected to the pan. This configuration will prevent the gauge
from interfering with the wind flow over the pan or from altering the solar
loading on the pan. A pipe connects the pan to the gauge keeping both at the
same “head”.

Evaporation pans need to be refilled from time to time. Depending on the local
rainfall, the pan should be filled to about 2 to 3 inches below the top. The
evaporation pan can be refilled automatically with the 255-620 Automatic
Refill Kit. More precise refill control can be done by programming the
datalogger to control a solenoid valve. Programming the datalogger for
partially draining the evaporation pan, using a second solenoid valve, may be
desirable if the site regularly experiences heavy rainstorms. Refer to the
section on Automatically Refilling the Evaporation Pan in this document for
more information.

NOTE

Fences or other deterrents are required to prevent animals from
using the evaporation pan as a watering trough.

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