Extech Instruments RF153 User manual

USER MANUAL
RF153 Brix Meter
User Manual Translations available
at www.extech.com

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Table Contents
1. Introduction 3
2. Safety 4
3. Specifications 8
4. Product Descriptions 10
5. Operation 12
6. Maintenance 20
7. Customer Support 22

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1. Introduction
Thank you for selecting the Extech RF153
Brix Meter. We ship this meter fully tested.
With proper use, it will provide years of
reliable service.
1-1 Features
•Wide measurement range (Brix 0~53%)
•Sugar content (Brix%) display
•Refractive Index (RI) measurement
•High resolution (Brix 0.1%)
•Auto Temperature Compensation ATC
•Dual LCD display
•Low power consumption
•IP65 Splash/Dust-proof
•Automatic measurement function
•Memory mode automatically stores up to
10 readings
•Sapphire coating is abrasion and
corrosion-resistant

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1-2 Applications
•Sugar, food and beverage production
inspection (fruit juices, soft drinks).
•Measure sugar concentration in cane,
fruits, vegetables, etc.
•Measure sugar content of fruit and plants
to determine maturity (helpful in seed
selection, and fertilization).
•For use in canning factories, breweries,
beverage plants, etc. for quality control
inspections to determine the degree of
sugar (Brix).
•For use in restaurants for sweetness
control.
•Control the concentration of industrial
fluids (cutting coolants, hydraulic fluids,
and antifreeze) to prevent corrosion.
2. Safety
Read the following safety information
carefully before attempting to operate or
service the meter. Only qualified personnel
should perform repairs.

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2-1 Safety Symbols
CE Certification.
Restricts the use of six
substances within electrical and electronic
equipment (EEE).
REACH（SVHC）This device does not
use materials or substances identified by
REACH to be potentially harmful or
hazardous.
IP (Int’l Protection Classification)
Conforms to the IP65 waterproof
specification.
You, as the end user, are legally bound (EU
Battery ordinance) to return all used batteries, disposal
in the household garbage is prohibited! You can hand
over your used batteries / accumulators at collection points
in your community or wherever batteries / accumulators are
sold!
Disposal: Follow the valid legal stipulations in respect of
the disposal of the device at the end of its lifecycle.

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2-2 Warning
To avoid injury:
•Please read the manual carefully to
ensure safe and correct use of this
device.
•Do not disassemble or modify the meter.
•Do not attempt to repair the meter. Only
qualified personnel may do so.
•This is high precision device, do not
apply excessive force or pressure to the
LCD or prism. Avoid shock and vibration.
•Do not use this meter near magnets or
magnetic fields.
•Do not use the meter near an open flame
or in flammable environments.
•Do not use this meter where the ambient
temperature exceeds the recommended
range of 10°C (50ºF) to 40°C (104ºF) or
in areas where the Relative Humidity
exceeds 80%.

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•If the temperature of the liquid that you
wish to measure is extreme, allow it to
settle to a workable temperature before
use.
•Do not use metal tools when sampling.
Metals can damage the prism surface.
•The prisms are coated for protection; do
not use acetone to clean the prism, as
this will harm the coating.
•After use, please follow the user manual
instructions for cleaning the prism. Close
the prism cover when storing.
•If the meter is to be stored for a long
period, remove the battery and close the
prism cover.
•Never use organic solvents for cleaning.

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3. Specifications
Model
Extech RF153
Sensor Element
Photodiode Array Detector
Measurements
Brix %
Temperature (oC/oF)
Refractive index (RI)
Ranges
Brix %
Water
4~60oC
(39 ～ 140oF)
0.0～53.0%
(10~40oC [50~104oF]
Automatic Temperature
Compensation)
RI
Water
4~60oC
(39 ～ 140oF)
1.3301~1.4374
Temperature
4.0～60.0oC (39.0～140.0oF)
Accuracy
(Water
73.4oF/23oC)
Brix ±0.2%
Temperature ±1oC(oF)
RI ±0.0003
Resolution
Brix: 0.1%
Temperature: 0.1oC(oF)
RI: 0.0001
Operating
conditions
10～40oC (50～104oF)
< 80% RH

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Storage
conditions
0～50oC (32～122oF)
< 80% RH
Response time
3 seconds
IP rating
IP65 splash/dust-proof
Data Hold
Freezes displayed reading
Low battery
indication
Four levels
Data storage
10 storage locations
Zero Function
Zeros the display
Auto Power Off
2 minutes (approximately)
Power supply
2 x ‘AAA’ batteries
Dimensions
113 x 60 x 38 mm
(4.4 x 2.4 x 1.5”)
Weight
120g (4.23 oz.) without battery
Accessories
Wrist strap, pouch, 2xAAA
batteries, and user manual

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4. Product Descriptions
4-1 Meter Description
1. Prism Cover
2. Prism
3. Measure (short press) / Zero (long
press) / Scroll up button (short presses
in Memory mode only)
4. Power ON/OFF (long press) / RCL
(short press to select Memory mode)
5. Unit button (short press for RI/BRIX;
long press for temperature units)
6. LCD display
7. Battery cover
8. Battery compartment secure screw

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4-2 LCD Description
1. Temperature reading
2. Measurement mode
3. Zero function
4. Brix% or RI reading
5. Temperature units
6. Battery status
7. Refractive index mode
8. Brix% mode

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5. Operation
5-1 Main Functions
Power ON／OFF
Long press to turn the meter on. All
display symbols will appear for 2 seconds.
After power-on, the meter will show the
ambient temperature along with dashes in
the main reading area. Long press to
turn the meter off.
Long press
→

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Select Measurement Units
Short press UNIT to select Brix unit (%) or
RI (refractive index). Long press UNIT to
select the temperature units (oC/oF).
Adding a sample to the prism
1. Use a dust-free cloth to wipe (gently)
the prism surface.
2. Use a non-metallic spoon or dropper
to place the sample on the prism (0.3
ml, approximately), to begin
measuring. As shown below.
Replacing a sample
1. Incline 45 degrees to allow the
measured sample to spill out along the

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grooves. As shown below.
2. Use water to flush the prism surface.
3. Use a dust-free cloth to wipe the prism
surface.
Auto Measurements
After placing the measurement liquid on the
prism, close the prism cover to start
measuring. The measurement result will
display on the LCD and save to memory
automatically (see Section 5-2). If ERR is
shown, an error has occurred, refer to
Section 5-3-2.

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Manual Measurements
After placing the measurement liquid, press
Mto start measuring. The measurement
result will display on the LCD and save to
memory automatically (see Section 5-2). If
ERR is displayed, an error has occurred,
please refer to Section 5-3-2.
Press M
→ → →
Zero Calibration
Placed distilled or tap water on the prism,
long press Mto access the zero function.
Long press M
→ → →
•Perform a zero calibration before each
use.
•Temperature of distilled/tap water
should equal ambient temperature.

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5-2 Memory/Measurement modes
Mode selection
Short press RCL to switch between the
Measurement mode and the Memory mode.
Memory Mode
When you access the Memory datalogger
mode, “dat #” flashes before showing the
stored readings.
Short press RCL → →
Use the button to scroll through the
stored readings.
Measurement Mode
When you select the Measurement mode,
dashes will display on the LCD screen.
Short press RCL →

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View Stored Readings
In Memory mode, short press to step
through up to 10 logged readings in
sequence.
→
→ Press
→ →
If a memory location is empty, the LCD will
display dashes for Temperature and Brix.
Clear Stored Readings
To clear all stored readings: In Memory
mode, long press Muntil “CLr DATA”
flashes once and then returns to “dat 1”.
Long press M
→→→

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5-3 LCD icons and alerts
5-3-1 Hi/Lo Alerts
The Hi or Lo Alert will appear under these
conditions:
•When ambient or sample temperature is
>40oC (104oF) or <10oC (50oF). The
temperature units will also flash. The
Brix reading will still display but the
accuracy will not be optimum; use for
reference only.
→ →
•When the Brix or RI reading is out of
range. (Brix >53% or <0%)
Note: When the Brix of the sample reads
low, perform a zero calibration (see
Section 5-1).

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5-3-2 Error Messages
Error 1: Prism Cover Error
During a measurement, the prism cover
was opened/closed, or the ambient light
was too strong. Close cover and try again.
Error 2: No Water Error
There is no water or there is an insufficient
amount of sample on the prism surface to
perform a measurement.
Error 3: Temperature Over Range
When the sample temperature (measured
on the prism surface) is out of range, the
accuracy will not be optimum (< 4oC [39.2oF]
or > 60oC [140oF]).

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Note that measurement data is not
automatically stored when an error
message is showing. Contact Extech if an
error is persistent and does not clear.
6. Maintenance
Cleaning the prism
Clean the prism surface immediately after
each measurement.
1. Use a cotton swab dipped in quality
alcohol (over 99%) and wipe in
concentric circles; avoid using acetone.
2. Use a dust-free cloth to wipe the surface
after using the alcohol.
3. Store in a dry and shaded area.
Cleaning the housing
Clean with soap and water using a damp
sponge or soft cloth.
Maintenance Notes
Do not use organic solvents to clean the
meter. Remove the batteries when storing
the meter. Close the prism cover when not
in use.