KERN ORA 4 UA (01) PDF Document

1. Prism cover

2. Prism surface

3. Adjustment screw

4. Eyepiece with rubber eyeshade

5. Diopter adjustment ring

6. Optical tubes with rubber grip

7. Storage box

8. Pipette

9. Refractometer

10. Calibration liquid (Distilled water)

11. Adjustment tool

12. Cleaning cloth

Carefully read through the operating manual even if you have prior experience with KERN refractometers.

► 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.

After unpacking, check that all listed parts have been supplied:

► Refractometer

► Storage box

► Pipette

► Adjustment tool

► Cleaning cloth

► Calibration liquid (Distilled water)

Replace damaged or faulty parts immediately and do not put them into operation.

Remove the protective film (if present) from the prism surface [2] and check that the rubber eye-cup [4] is fitted correctly.

1. 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.

2. Rotate the eyepiece [5] to adjust it for your eyesight, until you can see the scale sharply.

3. Open the prism cover [1].

4. 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.

5. Now apply a few drops of the calibration liquid [10] onto the prism surface [2].

6. 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].

7. Wait about 30 seconds to allow the temperatures of the fluid and prism to equalise.

8. Look through the eyepiece [4] while pointing the refractometer’s prism surface [2] at a bright light source.

9. 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].

10. 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. The calibration value for the KERN ORA 4 UA is 0 °C EG / PG / CW.

11. Repeat step 4 (cleaning).

The ambient/room temperature and the sample temperature influence the refractometer measuring result. The KERN ORA 4 UA is equipped with an automatic temperature compensation (ATC). Between +10°C and +30°C, measurement differences due to temperature changes are automatically compensated.

To ensure correct measurement, the device should be adjusted (calibrated) before measurements are carried out. Please make sure your hands are dry before handling the measuring device.

1. Make sure your hands are dry before handling the refractometer.

2. Open the prism cover [1] and use the supplied pipette [8] to apply a few drops of the sample liquid onto the prism surface [2]. Close the prism cover [1]. Spread the liquid evenly by pressing down on the prism cover [1] and eliminate any air bubbles present.

3. Hold the device horizontally and wait about 30 seconds (for optimal temperature equalisation between the sample and device).

4. View the measurement scale through the eyepiece [4]. Point the prism surface [2] of the refractometer at a bright light source while doing this.

5. Rotate the adjustment ring [5] on the eyepiece [4] to adjust the focus.

6. The boundary line will move on the measurement scale depending on the concentration. This bright/dark boundary line shows the result on the scale.

7. The instruments have a marking on the scale at 32.5% urea. That indicates the target value of the urea concentration in AdBlue®.

8. Carefully clean the supplied pipette [8] and the refractometer after carrying out the measurement.

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.

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].

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 refractometer to maximise its life and optimise measurement results.

Store the refractometer in a dry, non-corrosive environment, preferably between 10 °C and 30 °C.

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.

The product may differ slightly from the illustrations. Avoid exposing the refractometer to direct sunlight. Never bring the refractometer into contact with solvents.