This instrument measures the refractive index of a sample. The measurement is displayed in % Brix. 1. Zero Adjustment Cover the prism with distilled water (several drops will suffice). Close the cover plate and rotate the adjustment screw until the light/dark boundary (shadowline) lines up with the zero line. After the zero adjustment, clean the prism with a soft cloth. 2. Sample Preparation and Reading To take a sample reading, simply place a few drops of a sample liquid on the measurement prism at the end of the instrument. Close the prism cover plate so that the liquid spreads across the entire surface of the prism without air bubbles or dry spots (see diagram). Allow the sample to remain on the prism for approximately 30 seconds. Brix Refractometers Models RF10 and RF15 (with ATC) While holding the instrument under a light source, look through the eyepiece. The sucrose concentration is determined by the intersection of Bad Bad Good the boundary of the light and dark fields (known as the shadowline) on the printed scale. If the scale appears out of focus, the eyepiece may be adjusted by rotating the knurled portion of the eyepiece. The instrument also features an eye-guard to prevent stray light from entering the eyepiece and causing reflections. Introduction Congratulations on your purchase of the Extech RF10 or RF15 Brix Refractometer. Precision optical instruments should be handled gently; avoid touching the optical surface. Careful use of these instruments will provide years of reliable service. Specifications Range Resolution Dimensions Weight It may be necessary to adjust the position of the light source to maximize the contrast of the shadowline. 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. Note: The Distilled water temperature, used for zero adjustment, and the sample liquid temperature should be the same. If the temperature of the samples fluctuates, zero the refractometer every 30 minutes (RF10 only). 0 to 32% Brix 0.2% RF10: 6.6 x 1.3 x 1.3" (168 x 32 x 32mm); RF15: 6.3 x 1.4 x 1.4" (159 x 35 x 35mm) RF10: 3.2 oz. (91g); RF15: 7 oz. (200g) Description 1. Eyepiece 2. Mirror Tube 3. Adjustment screw 4. Cover Plate 5. Prism O Operation User's Guide 5 4 3 2 1 3. Temperature Compensation (RF15 has Auto Temp. Comp.) Temperature is one of the single most important factors influencing accurate refractometer readings and is one of the largest sources of measurement error. Temperature compensation relieves the user of the responsibility to measure temperature and apply a correction factor when taking readings. The RF15 makes this correction automatically. When ambient temperature strays 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). The RF10 Refractometer has been designed for use with a 20°C standard temperature. Therefore, if the temperature of the measurement deviates from 20°C, the reading must be manually compensated in accordance with the Temperature Compensation Table below. Example: A reading of 20% at 28°C is compensated thusly: 20% + 0.62%=20.62%. Copyright © 2005 Extech Instruments Corporation. All rights reserved including the right of reproduction in whole or in part in any form. Temperature Compensation Table (Referenced To 20 C) % oC 10 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 30 5 10 15 0.58 0.51 0.47 0.42 0.37 0.31 0.25 0.19 0.13 0.06 0.59 0.54 0.49 0.44 0.38 0.32 0.26 0.20 0.13 0.07 0.61 0.55 0.50 0.44 0.39 0.33 0.27 '0.20 0.14 0.07 0.07 0.14 0.21 0.28 0.35 0.43 0.51 0.59 0.67 0.75 0.07 0.14 0.21 0.29 0.36 0.44 0.52 0.60 0.68 0.77 0.07 0.14 0.22 0.29 0.37 0.44 0.53 0.61 0.69 0.78 20 25 30 35 40 45 50 55 Subtract the following from the measurement 0.64 0.67 0.69 0.71 0.72 0.74 0.74 0.74 0.58 0.61 0.63 0.65 0.65 0.67 0.67 0.67 0.52 0.55 0.57 0.58 0.58 0.60 0.60 0.60 0.45 0.49 0.50 0.51 0.51 0.53 0.53 0.53 0.40 0.42 0.43 0.44 0.44 0.45 0.45 0.45 0.34 0.35 0.36 0.37 0.37 0.38 0.38 0.38 0.28 0.28 0.29 0.30 0.30 0.30 0.31 0.31 0.21 0.21 0.22 0.22 0.23 0.23 0.23 0.23 0.14 0.14 0.15 0.15 0.15 0.15 0.15 0.15 0.07 0.07 0.07 0.08 0.08 0.08 0.08 0.08 Add the following to the measurement 0.07 0.07 0.08 0.08 0.08 0.08 0.08 0.08 0.14 0.15 0.15 0.16 0.16 0.16 0.16 0.16 0.22 0.23 0.23 0.23 0.23 0.24 0.24 0.24 0.30 0.30 0.31 0.31 0.31 0.31 0.31 0.32 0.38 0.38 0.39 0.39 0.40 0.40 0.40 0.40 0.46 0.46 0.47 0.47 0.48 0.48 0.48 0.48 0.54 0.55 0.55 0.56 0.56 0.56 0.56 0.56 0.62 0.63 0.64 0.64 0.65 0.65 0.64 0.64 0.70 0.71 0.72 0.73 0.73 0.73 0.73 0.73 0.79 '0.80 '0.81 0.81 0.81 0.82 0.81 0.81 60 65 70 0.75 0.68 0.60 0.53 0.45 0.38 0.31 0.23 0.15 0.08 0.76 0.68 0.61 0.53 0.45 0.38 0.31 0.23 0.15 0.08 0.77 0.69 0.61 0.53 0.46 0.38 0.31 0.23 0.15 0.08 0.08 0.16 0.24 0.32 0.40 0.48 0.56 0.64 0.72 0.81 0.08 0.16 0.23 0.31 0.39 0.47 0.55 0.64 0.72 0.80 0.08 0.15 0.22 0.31 0.39 0.47 0.55 0.63 0.71 0.79 Source: International Commission for Uniform Methods of Sugar Analysis (1966) International Brix% Scale Brix to Refractive Index (nD) Conversion Table % 0 1 2 3 4 nD 1.333 1.3344 1.3359 1.3373 1.3388 % 15 16 17 18 19 nD 1.3557 1.3573 1.3589 1.3605 1.3622 % 30 31 32 33 34 nD 1.3811 1.3829 1.3847 1.3866 1.3884 % 45 46 47 48 49 nD 1.4097 1.4118 1.4138 1.4159 1.418 % 60 61 62 63 64 nD 1.4419 1.4442 1.4464 1.4488 1.4511 % 75 76 77 78 79 nD 1.4778 1.4804 1.4829 1.4855 1.4881 5 6 7 8 9 1.3403 1.3418 1.3433 1.3448 1.3463 20 21 22 23 24 1.3638 1.3655 1.3672 1.3689 1.3706 35 36 37 38 39 1.3903 1.3922 1.3941 1.396 1.3979 50 51 52 53 54 1.42 1.4222 1.4243 1.4264 1.4286 65 66 67 68 69 1.4534 1.4558 1.4582 1.4606 1.463 80 81 82 83 84 1.4907 1.4933 1.496 1.4987 1.5014 10 11 12 13 14 1.3478 1.3494 1.3509 1.3525 1.3541 25 26 27 28 29 1.3723 1.374 1.3758 1.3776 1.3793 40 41 42 43 44 1.3998 1.4018 1.4037 1.4057 1.4077 55 56 57 58 59 1.4308 1.4329 1.4352 1.4374 1.4396 70 71 72 73 74 1.4654 1.4678 1.4703 1.4728 1.4753 85 86 87 88 89 1.5041 1.5068 1.5096 1.5123 1.5151 Source: International Sugar Analysis Committee Warranty EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies on 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 at (781) 890-7440 ext. 210 for authorization or visit our website at www.extech.com (click on ‘Contact Extech’ and go to ‘Service Department’ to request an RA number). A Return Authorization (RA) number must be issued before any product is returned to Extech. 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. Extech 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. Extech'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. Manual Version No. 2.1 November 2005