Installation Guide

RF20-en-US_v2.4 3/15
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USER GUIDE
Portable Salinity Refractometer with ATC
Model RF20
Introduction
Congratulations on your purchase of the Extech RF20
Handheld Salinity Refractometer with Automatic Temperature
Compensation. Precision optical instruments should be
handled gently; avoid touching the optical surface. Careful use
of this instrument will provide years of reliable service.
Description
1. Eyepiece
2. Mirror tube
3. Adjust screw
4. Cover plate
5. Prism
Field of view
Operation
The instrument measures the refractive index of the sample and
displays the result in parts per thousand (
0
/
00
) and specific
gravity (d
20
/
20
).
1. Zero Adjustment
Cover the prism with a few drops of distilled water from the
included vial. Close the cover plate and rotate the adjusting
screw so that the light/dark boundary line (known as the
shadow-line) evens up with the zero line. After the zero
adjustment, clean the prism with soft cloth.
2. Sample Preparation and Measurement Readings
To take a reading, place a few drops of a sample liquid on
the measurement prism. Ensure that enough solution is
added to the prism in order to cover the entire prism. Close
the prism so that the liquid spreads across the entire surface
of the prism without air bubbles or dry spots (see diagrams
below). Allow the sample to remain on the prism for
approximately 30 seconds.
While holding
the instrument
under a light
source, look
through the
eyepiece. The
salinity
concentration
is determined
by the
intersection of
the boundary
of the light and
dark fields
(known as the shadow-line) on the printed scale. The left
side of the scale indicates the specific gravity and the right
side parts per thousand. If the scale appears out of focus, the
eyepiece may be adjusted by rotating the knurled portion.
The instrument also features an eye guard to prevent stray
light from entering the eyepiece and causing reflections.
It may be necessary to adjust the position of the light source
to maximize the contrast of the shadow-line. Under normal
conditions, optimal contrast is obtained by holding the
instrument underneath and perpendicular to a light source.
Once a reading has been taken, wipe dry with a clean cloth
(do not wash or rinse) and place the instrument in the
supplied plastic case. Store the instrument in a safe, dry
environment.
3. Automatic Temperature Control (ATC)
Temperature is the single most important factor influencing
refractometer readings and is one of the largest sources of
measurement error. However, this device incorporates
automatic temperature compensation and the concern for
temperature fluctuations in sample liquids is alleviated. When
ambient temperature varies from 68°F (20°C), readings are
automatically adjusted to compensate for temperature
variance between 50°F to 86°F (10°C to 30°C).
Specifications
Scale Range Resolution
Parts Per Thousand 0 to 100
0
/
00
1
0
/
00
Specific Gravity 1.000 to 1.070 d
20
/
20
0.001 d
20
/
20
Dimensions: 7.6 x 1.5 x 1.5" (194 x 38 x 38mm)
Weight: Approx. 8.0 oz. (227g)
Calibration and Repair Services
FLIRSystems,Inc.offersrepairandcalibrationservicesforthe
ExtechInstrumentsproductswesell.NISTcertificationformost
productsisalsoprovided.CalltheCustomerService
Departmentforinformationoncalibrationservicesavailablefor
thisproduct.Annualcalibrationsshouldbeperformedtoverify
meterperformanceandaccuracy.Technicalsupportand
generalcustomerserviceisalsoprovided,refertothecontact
informationprovidedbelow.
Warranty
FLIRSystems,Inc.warrantsthisExtechInstrumentsbranddevicetobefreeof
defectsinpartsandworkmanshipforoneyearfromdateofshipment(asixmonth
limitedwarrantyappliestosensorsandcables).Ifitshouldbecomenecessaryto
returntheinstrumentforserviceduringorbeyondthewarranty
period,contact
theCustomerServiceDepartmentforauthorization.Visitthewebsite
www.extech.comforcontactinformation.AReturnAuthorization(RA)number
mustbeissuedbeforeanyproductisreturned.Thesenderisresponsiblefor
shippingcharges,freight,insuranceandproperpackagingtopreventdamagein
transit.Thiswarrantydoesnotapply
todefectsresultingfromactionoftheuser
suchasmisuse,improperwiring,operationoutsideofspecification,improper
maintenanceorrepair,orunauthorizedmodification.FLIRSystems,Inc.specifically
disclaimsanyimpliedwarrantiesormerchantabilityorfitnessforaspecific
purposeandwillnotbeliableforanydirect,indirect,incidentalor
consequential
damages.FLIR’stotalliabilityislimitedtorepairorreplacementoftheproduct.
Thewarrantysetforthaboveisinclusiveandnootherwarranty,whetherwritten
ororal,isexpressedorimplied.
Copyright©2013‐2015FLIRSystems,Inc.
Allrightsreservedincludingtherightofreproductioninwholeorinpartinany
form
www.extech.com
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SupportLines:U.S.(877)439‐8324;International:+1(603) 324‐7800
TechnicalSupport:Option3;E‐mail:[e-mail]
Repair&Returns:Option4;E‐mail:[e-mail]
Productspecificationsaresubjecttochangewithoutnotice
Pleasevisitourwebsiteforthemostup‐to‐dateinformation
www.extech.com
FLIRCommercialSystems,Inc.,9
TownsendWest,Nashua,NH03063USA
ISO9001Certi
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ied