KERN ORA 3AA-AB Beer Refractometer Analogues User Manual
- October 30, 2023
- KERN
Table of Contents
KERN ORA 3AA-AB Beer Refractometer Analogues
Product Information
| Model | Measuring Range | Scales | Dimensions | Net Weight |
|---|---|---|---|---|
| KERN ORA 3AA/AB | 0-32% Brix, 1.000-1.130 SG wort | 0.2% Brix, 0.001 SG wort | ||
| 178x40x40mm | 0.145kg | |||
| KERN ORA 4AA/AB | Not specified | Example scale: ORA 3AA/AB | 189x40x40mm |
0.155kg
Product Usage Instructions
General Information
The refractometer is a measuring instrument used to determine the refractive index of transparent substances in the liquid or solid state. It observes the behavior of light as it passes from a prism with known properties to the substance being tested. It is important to use the refractometer only for its intended purposeand not for any other purposes, as it may be hazardous. The manufacturer will not be liable for any damages caused by improper use.
Warranty
The warranty will be void if:
- The instructions in the operating manual are not followed
- The refractometer is used for purposes other than those described
- The device housing is modified or opened
- Mechanical damage and/or damage resulting from media, liquids, or natural wear and tear occur
Basic Safety Information
It is important to follow the instructions in the operating manual. Even if you have prior experience with KERN refractometer, it is recommended to carefully read through the operating manual. Please note that every language version includes anon-authoritative translation, and the original German document is the definitive version.
Warning
Acids should not come into contact with skin or eyes. If acid comes into contact with skin, flush with copious amounts of water and shower if larger areas of skin are affected. If acid comes into contact with eyes, keep the eyelid open and flush the eye with running lukewarm water from the outer corner to the inner corner for at least 15 minutes. Then consult a doctor or ophthalmologist immediately. Thoroughly clean the refractometer after each use.
Technical data
Models KERN| Measuring range and Scales| Scale graduation Accuracy| Dimensions
Product
| Net Weight
---|---|---|---|---
Ora 3AA/AB| 0-32% Brix
1.000-1.130 SG wort
| 0,2% Brix
0.001 SG wort
| 178x40x40mm| 0.145kg
Ora 4AA/AB| 0-18° Plato| 0.1° P| 189x40x40mm| 0.155kg
Description
- Prism cover
- Prism surface
- Adjustment screw
- Eyepiece with rubber eyeshade
- Diopter adjustment ring
- Optical tubes with rubber grip
- Storage box
- Pipette
- Refractometer
- Calibration liquid (Distilled water)
- Adjustment tool
- Cleaning cloth
General information
Intended use:
The refractometer is a measuring instrument for determining the refractive index of transparent substances in the liquid or the solid state. It is used to observe the behaviour of light as it passes from a prism with known properties to the substance being tested. Use of the refractometer for other purposes is contrary to its intended use and may be hazardous. The manufacturer shall not be liable for any damages caused by improper use.
Warranty
The warranty shall be void in the event of:
- Failure to observe the instructions in the operating manual
- Use for purposes other than those described
- Modifications or opening the device housing
- Mechanical damage and/or damage resulting from media, liquids, natural wear and tear
Basic safety information
Follow the instructions in the operating manual
- Carefully read through the operating manual even if you have prior experience with KERN refractometers.
- Every language version includes a non-authoritative translation. The original German document is the definitive version.
Warning
- Do not let acids come into contact with skin or eyes. If acid comes into contact with skin, flush with copious amounts of water. Shower if larger areas of skin are affected.
- If acid comes into contact with eyes, keep the eyelid open and flush the eye with running lukewarm water from the outer corner to the inner corner. Flush eyes for at least 15 minutes. Then consult a doctor or ophthalmologist immediately.
- Thoroughly clean the refractometer after each use.
- The refractometer must not be exposed to extreme temperatures, high mechanical stresses, strong direct sunlight or high humidity.
- This refractometer is not a toy. Keep out of reach of children.
- Make sure that you will not be hit by anything else while you are using the refractometer, as this could cause serious eye injuries
- The rubber eyeshade may cause irritation when in prolonged contact with the skin. If this happens, consult your doctor.
- Do not touch the lenses with your fingers.
Supplied items
After unpacking and before using the device for the first time, check that all listed parts have been supplied. Replace damaged or faulty parts immediately and do not put them into operation.
- Refractometer
- Storage box
- Pipette
- Adjustment tool
- Cleaning cloth
- Calibration liquid (Distilled water)
Before the first use
Remove the protective film (if present) from the prism surface [2] and check that the rubber eye-cup [4] is fitted correctly.
Use/measurement
The refractometer can be used to quickly and accurately determine the refractive index of transparent substances, liquid or solid ones. To ensure correct measure-ment, the measuring device should be adjusted before measurements are carried out. Please make sure your hands are dry before handling the measuring device.
Zero point calibration
- Hold up the refractometer against a sufficiently bright light source and look through the eyepiece [5], holding the rubber eyeshade [4] closely against your eye/glasses.
- Rotate the eyepiece [5] to adjust it for your eyesight, until you can see the scale sharply.
- Open the prism cover [1].
- Thoroughly clean the prism [2] and the underside of the prism cover [1] using a soft cloth or soft paper (with alcohol if necessary) and wipe dry.
- Now apply a few drops of the calibration liquid [10] onto the prism surface [2].
- Close the prism cover [1]. The amount of fluid should be sufficient to moisten most of the prism surface. There should not be any air bubbles between the measuring prism [2] and prism cover [1].
- Wait about 30 seconds to allow the temperatures of the fluid and prism to equalise.
- Look through the eyepiece [4] while pointing the refractometer‘s prism surface [2] at a bright light source.
- Through the eyepiece [4], you will see a bright and a blue field. The boundary line between them shows the measured value on the scale which is also visible through the eyepiece [4].
- Use the supplied adjustment tool [11] to turn the adjustment screw [3] behind the prism surface [2] (under the rubber cap), and adjust the scale so that the measuring device is optimally set up by moving the boundary line upwards or downwards. Calibration value ORA 3AA/3AB: 0 % (Brix) / 1.000 (SG wort) Calibration value ORA 4AA/4AB: 0 °P (Plato)
- Repeat step 4 (cleaning).
Important:
The ambient/room temperature and the sample temperature influ-ence the
refractometer measuring result. The scales of the refractometer models, which
have “AB” in its name, are designed for an ambient temperature of +20 °C! If
the measurements are carried out at a temperature other than +20 °C, the
results must be correspondingly corrected. A correction table can be found in
the annex, Point 14. Refractometer models, which have “AA” in its name, are
equipped with an automatic temperature compensation (ATC). Between +10°C and
+30°C measurement differences due to temperature changes are automatically
compensated.
Additional advice
It is important that the samples being measured are representative samples. For samples that evaporate easily, measurements should be carried out quickly. The samples should be at the same temperature as the measuring instrument in order to achieve an accurate result.
Measuring procedure
- Make sure your hands are dry before handling the refractometer.
- Open the prism cover [1] and use the supplied pipette [8] to apply a few drops of the sample liquid [8] onto the prism surface [2]. Close the prism cover [1]. Spread the liquid evenly by pressing down on the prism cover [1] and elimi-nate any air bubbles present.⇨
- Hold the device horizontally and wait about 30 seconds (for optimal tempera-ture equalisation between the sample and device).
- View the measurement scale through the eyepiece [4]. Point the prism surface [2] of the refractometer at a bright light source while doing this.
- Rotate the adjustment ring [5] on the eyepiece [4] to adjust the focus.
- The boundary line will move on the measurement scale depending on the concentration. This bright/dark boundary line shows the result on the scale.
- If the temperature deviates from +20 °C and a refractometer without ATC is used, correct the measured result using the corresponding value from the temperature correction table [13].
- Carefully clean the supplied pipette [8] and the refractometer after carrying out the measurement.
Important:
After every measurement, use a lint-free, absorbent cloth to remove the fluids
from the prism surface [2] and prism cover [1]. Then carefully clean the prism
and prism cover using a cloth moistened with water or if necessary alcohol,
and dry both parts using a soft, dry and lint-free cloth. Avoid rubbing the
prism [2].
Cleaning and maintenance
- Clean the refractometer using a soft, lint-free cloth moistened with either water or, if necessary, alcohol. Do not use any aggressive or abrasive cleaning agents. Never immerse the device in water or hold it under running water. Never handle the device with wet or damp hands.
- Never touch the measuring prism [2] with hard tools made from plastic, wood, rubber, metal, glass etc. Hard objects can quickly damage the relatively soft prism glass, resulting in measurement errors.
- The refractometer is maintenance-free.
- Cleaning should be carried out immediately before and after each use of the refrac-tometer to maximise its life and optimise measurement results.
Storage
Store the refractometer in a dry, non-corrosive environment, preferably between 10 °C and 30 °C.
Service
After reading this operating manual, if you have any questions about setting
up
or using the refractometer, or if any unexpected problem occurs, please
contact your dealer. The device housing may only be opened by trained service
technicians authorised by KERN.
Disposal
The packaging consists of environmentally friendly materials which can be disposed of via local recycling facilities. The device and storage box should be disposed of by the operator in accordance with applicable national or regional regulations at the place of use.
Additional information
The product may differ slightly from the illustrations. Avoid exposing the refracto-meter to direct sunlight. Never bring the refractometer into contact with solvents.
Brix to refractive index (nD) conversion table
Data from „ICUMSA“ International Commission for Uniform Methods of Sugar Analysis, at 20 °C and 589 nm wavelength.
Refractive
BRIX index
% nD
| 60 1.44193
61 1.44420
62 1.44650
63 1.44881
64 1.45113
65 1.45348
66 1.45584
67 1.45822
68 1.46061
69 1.46303
70 1.46546
71 1.46792
72 1.47037
73 1.47285
74 1.47535
75 1.47787
76 1.48040
77 1.48295
78 1.48552
79 1.4881
80 1.49071
81 1.49333
82 1.49597
83 1.49862
84 1.50129
85 1.50398
---|---
Refractive
BRIX index
% nD
| 30 1.38115
31 1.38296
32 1.38478
33 1.38661
34 1.38846
35 1.39032
36 1.39220
37 1.39409
38 1.39600
39 1.39792
40 1.39986
41 1.40181
42 1.40378
43 1.40576
44 1.40776
45 1.40978
46 1.41181
47 1.41385
48 1.41592
49 1.41799
50 1.42009
51 1.42220
52 1.42432
53 1.42647
54 1.42862
55 1.43080
56 1.43299
57 1.43520
58 1.43743
59 1.43967
Refractive
BRIX index
% nD
| 0 1.33299
1 1.33442
2 1.33586
3 1.33732
4 1.33879
5 1.34026
6 1.34175
7 1.34325
8 1.34476
9 1.34629
10 1.34782
11 1.34937
12 1.35093
13 1.35250
14 1.35408
15 1.35568
16 1.35729
17 1.35891
18 1.36054
19 1.36218
20 1.36384
21 1.36551
22 1.36720
23 1.36889
24 1.37060
25 1.37233
26 1.37406
27 1.37582
28 1.37758
29 1.37936
Annex
Table 1: International Temperature Correction Table for °Brix (% sugar gradient) Correct the result by the following values (refractometer must be correctly adjusted at 20 °C).
| % Brix reading
0.0 5.0
|
---|---|---
10.0| 15.0| 20.0| 25.0| 30.0| 35.0| 40.0|
45.0| 50.0| 55.0| 60.0| 65.0| 70.0| 75.0|
80.0| 85.0
Temperature °C
| 10.0
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
22.0
23.0
24.0
25.0
26.0
27.0
28.0
29.0
30.0
| -0.53
-0.49
-0.44
-0.40
-0.34
-0.29
-0.24
-0.18
-0.12
-0.06
0.00
0.06
0.13
0.20
0.27
0.34
0.42
0.50
0.58
0.66
0.74
| -0.56
-0.52
-0.47
-0.41
-0.36
-0.31
-0.25
-0.19
-0.13
-0.06
0.00
0.07
0.14
0.21
0.28
0.35
0.43
0.51
0.59
0.67
0.75
| -0.59
-0.54
-0.49
-0.43
-0.38
-0.32
-0.26
-0.20
-0.13
-0.07
0.00
0.07
0.14
0.21
0.29
0.36
0.44
0.52
0.60
0.68
0.77
| -0.62
-0.57
-0.51
-0.45
-0.39
-0.33
-0.27
-0.20
-0.14
-0.07
0.00
0.07
0.14
0.22
0.29
0.37
0.45
0.53
0.61
0.69
0.78
| -0.65
-0.59
-0.53
-0.47
-0.40
-0.34
-0.28
-0.21
-0.14
-0.07
0.00
0.07
0.15
0.22
0.30
0.38
0.46
0.54
0.62
0.70
0.79
| -0.67
-0.61
-0.55
-0.48
-0.42
-0.35
-0.28
-0.21
-0.14
-0.07
0.00
0.07
0.15
0.23
0.30
0.38
0.46
0.55
0.63
0.71
0.80
| -0.69
-0.63
-0.56
-0.50
-0.43
-0.36
-0.29
-0.22
-0.15
-0.07
0.00
0.08
0.15
0.23
0.31
0.39
0.47
0.55
0.64
0.72
0.81
| -0.71
-0.64
-0.57
-0.51
-0.44
-0.37
-0.30
-0.22
-0.15
-0.08
0.00
0.08
0.15
0.23
0.31
0.39
0.47
0.56
0.64
0.73
0.81
| -0.72
-0.65
-0.58
-0.52
-0.44
-0.37
-0.30
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.23
0.31
0.40
0.48
0.56
0.64
0.73
0.81
| -0.73
-0.66
-0.59
-0.52
-0.45
-0.38
-0.30
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.24
0.32
0.40
0.48
0.56
0.65
0.73
0.82
| -0.74
-0.67
-0.60
-0.53
-0.45
-0.38
-0.31
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.24
0.32
0.40
0.48
0.56
0.65
0.73
0.81
| -0.75
-0.68
-0.60
-0.53
-0.46
-0.38
-0.31
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.24
0.32
0.40
0.48
0.56
0.64
0.73
0.81
| -0.75
-0.68
-0.61
-0.53
-0.46
-0.38
-0.31
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.24
0.32
0.40
0.48
0.56
0.64
0.72
0.81
| -0.75
-0.68
-0.61
-0.53
-0.46
-0.38
-0.31
-0.23
-0.15
-0.08
0.00
0.08
0.16
0.23
0.31
0.39
0.47
0.55
0.64
0.72
0.80
| -0.75
-0.68
-0.60
-0.53
-0.46
-0.38
-0.31
-0.23
-0.15
-0.08
0.00
0.08
0.15
0.23
0.31
0.39
0.47
0.55
0.63
0.71
0.79
| -0.75
-0.67
-0.60
-0.53
-0.45
-0.38
-0.30
-0.23
-0.15
-0.08
0.00
0.08
0.15
0.23
0.31
0.39
0.46
0.54
0.62
0.70
0.78
| -0.74
-0.67
-0.60
-0.52
-0.45
-0.37
-0.30
-0.23
-0.15
-0.08
0.00
0.08
0.15
0.23
0.30
0.38
0.46
0.53
0.61
0.69
0.77
| -0.73
-0.66
-0.59
-0.52
-0.44
-0.37
-0.30
-0.22
-0.15
-0.07
0.00
0.07
0.15
0.22
0.30
0.37
0.46
0.52
0.60
0.68
0.75