ATAGO PRM-2000 A User manual

3641-E11
In-line Refractometer
PRM- 2000
Instruction Manual
Cat.No 3641
PRODUCT REGISTRATION & WARRANTY CARD
https://www.atago.net/registration/
english/registration.php

1
Contents
1. Precautions for Use .............................................................................................................................2
2. Refractive Index and Brix(%)...............................................................................................................5
3. Unpacking and Installation...................................................................................................................6
4. Names and Functions of Components ................................................................................................7
5. Mounting the Detection Section.........................................................................................................10
6. Mounting the Display Section ............................................................................................................13
7. Connecting the Detection Section to the Display Section .................................................................15
8. External Output..................................................................................................................................17
9. Turning On the Power........................................................................................................................21
10. Measurement Scale Settings.............................................................................................................22
11. Setting Measurement SET UP Mode.................................................................................................26
12. Measurement Procedure ...................................................................................................................49
13. Cleaning the Prism ............................................................................................................................50
14. Definitions of Error Messages ...........................................................................................................51
15. Availability of Parts ............................................................................................................................52
16. Specifications.....................................................................................................................................53
17. Dimensions........................................................................................................................................54
18. Repair Service and Warranty Period .................................................................................................55
19. ATAGO CO.,LTD. Service Centers ....................................................................................................56

2
1.Precautions for Use
Introduction
Thank you for purchasing the "In-line refractometer PRM-2000α".
The instrument utilizes the refraction created by the interface between the detection section's prism
surface and the sample to continuously measure the refractive index, Brix, concentration and ratio.
Before using your PRM-2000α, read this instruction manual carefully, and understand how to use it. After
reading this manual, keep it on hand for future reference.
In this manual "For safe use" describes the important items necessary for safety. Read it carefully.
For safe use--- Be sure to observe the following.
This operation manual describes the items which you are required to observe in order to use the
PRM-2000α safely, to prevent injury to you and other people and damage to your property. The explanation
of the indications and symbols of those items are as follows. Understand them first and then read the
following pages to use your PRM-2000α correctly.
Explanation of indications
WARNING
If this indication is neglected and the instrument is handled incorrectly,
serious injury or death may result.
CAUTION
If this indication is neglected and the instrument is handled incorrectly, injury
and/or property damage may result.
Explanation of symbols

This symbol denotes an item of which to be warned or cautioned.
The contents of warning are described in detail in or near the △.

This symbol denotes an action that must not be performed (a prohibited item).
The contents of prohibition are described in detail in or near the ○.

This symbol denotes an action that must be performed. The contents of instruction are
described in detail in or near the ●.
Handling of this instrument
WARNING
◇When measuring a substance harmful to the
human body, be aware of its properties and
wear protective gloves, mask, etc.

◇If the instrument begins to smell abnormally,
overheat, or emit smoke, turn off the power
switch and disconnect the power plug
immediately.Fire or malfunction may result if the
instrument is continued to be used. Ask your
ATAGO distributor for an inspection.

◇Do not attempt to repair, modify, or disassemble
the instrument yourself.
Improper servicing may result in fire, electrical
shock, or burns.

◇If the instrument is dropped or is subjected to a
strong shock, have it inspected by an ATAGO
distributor. Fire or malfunction may result if the
instrument is used.


3
Handling of this instrument (Continued)
CAUTION
◇Keep the detection section except for the wetted
sensor part away from water.
Do not operate the instrument while the
connecting ports of the display section is wet.
(The instrument is protected against submersion
in water, it may not be operated submerged in
water.) Do not place the display section in
places that are frequently wet or have constant
exposure to water.
◇Use of this instrument in a manner other than
the one stated in this instruction manual may
compromise the durability of the instrument.

◇If this instrument is used to measure very hot or
highly acidic samples, the prism may be
damaged resulting in inaccurate measurements.
◇Use only the included accessories which meet
specification requirements as described in this
instruction manual.

◇Do not measure a sample that can damage the
prism or the sample inlet unit. When the power
is turned ON, do not measure a sample that is
below -35˚C or above 165˚C.

◇If sample material has collected on the prism,
please refer to Page 50 "13.Cleaning the Prism"
of this manual for cleaning instructions.

◇Turn off the power switch before leaving the unit
out of serviced for an extended period of time.

◇When relocating the unit, pack it fully to guard
against shocks during transit and enclose it in
the corrugated fiberboard box in which it had
been delivered. 
◇Carefully read this instruction manual and fully understand the function and operation of each part of the
instrument before use.
◇Inspect each part of the instrument for damage or defects that may have occurred in the shipping or
manufacturing process.
◇Check the necessary operations such as zero setting according to the instruction manual.
◇The manufacturer shall not be liable for any and all damages resulting from uses of the instrument that
deviate from those intended by the manufacturer, which are the measurement of Brix, sugar content,
and concentration of liquid solutions.
◇The prism is a consumable item and is not covered under warranty.
Special care should be taken to avoid scratching or damaging the prism.
◇The manufacturer shall not be liable for any effect the use of this instrument may have on the
consumption or application of the measured materials or related processes, etc.
Handling of plug
WARNING
◇Do not insert the power plug in an outlet other
than AC100 to 240V.
Inserting the power plug in any other outlet may
result in short circuiting the unit, smoking or fire.

◇Do not use the power cable and plug if damaged
or broken.If used, fire, electrical shock, or burns
may result.For a new power cable and plug,
contact your ATAGO distributor.


4
Handling of plug (Continued)
CAUTION
◇Do not insert or
disconnect the power
plug with wet hands.

◇Be sure to hold and pull the plug when
disconnecting the power cable from the
outlet.
If the cable is pulled improperly, the plug
may be broken, and may result in fire or
electrical shock.

◇Ensure the grounding pin
is properly connected
when connecting the
power cable to an AC
outlet.

Connecting Compontents
WARNING
◇Turn off the power switch and unplug the unit from the AC outlet before connecting the individual
components with connecting cables. Connecting components while the unit power is on increases the
likelihood of electrical shock.

Conditions to be observed when using
Environmental conditions
◇Use the instrument at an altitude below 2,000m (above sea level).
◇Use the instrument indoors.
◇Use the instrument where the temperature is between 5 to 40˚C.
◇Do not leave the instrument in a location exposed to direct sunlight or near a heating unit where the
temperature may rise.
◇Do not change the environmental temperature of the instrument suddenly.
◇Do not place the instrument in a place where it may be subject to strong vibrations.
◇Do not use the instrument where there is much dust.
◇Do not leave the instrument where the temperature is extremely low.
◇Do not leave the instrument in a damp place.
◇Do not place or drop heavy objects on the instrument.
◇Use this instrument under the condition where humidity is 80% at 31˚C or lower, falling linearly to 50%
at 40˚C.
◇Main supply voltage fluctuation should not to exceed ±10% the nominal voltage.
◇Installation categories (Overvoltage Categories) : ｌｌ
◇The pollution degree is 2 (according to IEC60664).
Handling
◇Do not drop the instrument or subject it to any strong shock.
◇The power cable may be damaged by:
Bending the cable.
Pulling the cable.
Twisting the cable.
Placing the cable under heavy objects.
Catching the cable between objects.
Daily maintenance
◇If the instrument becomes dirty, wipe it with a soft cloth.
◇Do not use benzine, paint thinner, etc. to clean the instrument.

5
2.Refractive Index and Brix(%)
2-1. What is refractometer?
When a straw is placed into a glass filled with water, the straw appears to bend. When a straw is
placed into a glass filled with sugar water, the straw appears to bend much more sharply than in the
case of water alone.
This phenomenon is known as the refraction of light. The refractometer is an instrument that
measures the Refractive Index by utilizing this principle (the Refractive Index increases in proportion
to the concentration of the solution), and was developed by Dr. Ernst Abbe at the end of the 19th
century.
2-2. What is the Refractive Index?
If the Refractive Index of air under atmospheric pressure is 1,
then when light enters medium χ, the ratio of the sine of the
incident angle α measured against the phase boundary to the
sine of the refracting angle β is called the Refractive Index of
the mediumχ.
The Refractive Index varies with the wavelength of light and
temperature and is represented as follows:
For example, Refractive Index of water at 20˚C under the D-line is:
=1.33299(Generally expressed as nD = 1.33299.)
mThe Refractive Index is based upon the supposition that the Refractive Index in a vacuum is 1
and is called the absolute Refractive Index. Generally, however, this index is seldom used.
2-3. Brix(%) scale
The PRM-2000α is programmed with the Brix(%) scale, based on the Refractive Index of water (nD =
1.33299) as the reference (0%). The Brix(%) scale represents the weight of sucrose expressed by
percentage (sucrose weight in grams contained in 100 grams of sucrose solution).
Therefore, this scale corresponds with the sucrose concentration. However, most samples are
comprised of ingredients other than sugar. The total concentration of these ingredients is
represented by the Brix(%), so this makes the Brix(%) scale a practical tool for measuring
concentrations.
mThe Brix(%) scale is recommended by ICUMSA (International Committee of Uniform Method
of Sugar Analysis) and is expressed in % mas (Sucrose) in international units (SI unit).
2-4. Temperature correction
The Refractive Index of a substance varies with temperature. Thus, when using a refractometer to
measure the Refractive Index of a liquid, the measurement value will vary with the sample
temperature.The Brix or concentration value displayed by this product is automatically compensated
by the internal software based on the measured temperature and the same value is always displayed
as if measurements were made at 20˚C (in case of a sample temperature of 5 to 90˚C).
Air
Medium χ
n=1
α
β
nχ=
sin α
sin β
n: Represents the Refractive Index
t: Temperature (˚C)
D: Sodium D-line (589nm)

6
3.Unpacking and Installation
3-1. Unpacking
①Unpack the unit and visually check for any damages that may have occurred during transit.
②Make sure that the following components are included:
PRM-2000α detection section ....................1
PRM-2000α calculation display section ......1
Detection section - display section connecting
cable (hereinafter the DS-2 cable)..............1
Recorder output cable (4-20mA) ................1
3K clamp band 3S ......................................1
O-ring (Silicon)............................................1
O-ring (EPDM)............................................1
Plain washer...............................................4
Hexagon socket head bolt(cross-recessed
for assembling a spring washer) ................2
Instruction manual (this manual) ................1
Calibration Certificate.................................1
NThese components are available with PRM-2000α and built to standard specifications.
3-2. Installation
mWhen using the display section's terminals, be sure to remove the metal caps, as well as the
rubber caps (x 3) (Fig.3-1).
①Run the unit from a power supply of 100V AC to 240V AC, 50/60Hz.
②Install the unit in an ambient temperature range of 5 to 40˚C.
③This unit contains precision components.
Avoid installing this unit in places that are exposed to direct sunlight or near a heat source, or where
dust or corrosive gases may accumulate.
④Install this unit in a location that is protected from strong vibration.
Exercise care during installation to avoid any impact or shock to the instrument, as such stress may
affect the performance of electronic components.
⑤Do not touch the prism surface with your hand. Finger-prints left on the prism surface may cause
sample to build up on the prism.
In the event of contact with the prism surface, clean carefully with a soft tissue soaked with ethyl
alcohol.
In order to prevent scratches, never clean the prism surface using abrasive materials.
Fig.3-1

7
4.Names and Functions of Components
4-1. Detection Section (Fig.4-1・Fig.4-2)
①Prism
Sample material contacts the prism surface to
allow for the measurement of its refractive
index, Brix and/or concentration.
②Sample inlet unit mounting part
Mount the sample inlet unit on this part.
③Detection section - Display section connection
terminal
Connect the DS-2 cable to this terminal.
④Air cooling fin
Dissipates heat to preserve the unit's
electronic components when measuring high
temperature samples.
⑤Temperature sensor
⑥Mark to show the position of the thermo
sensor.
Fig.4-1
Fig.4-2
⑥
③
①
②
④
⑤

8
4-2. Display Section
(1) Operator section (Fig.4-3)
①START/STOP key
Start or stops measurement (turning the power
on automatically begins measurement).
②SCALE key
Chooses from among the measurement value
display modes nD (refractive index), Brix
(sucrose reading scale) and the SET UP
mode.
③ENTER key
Used to carry out reference level adjustment
and manipulate the SET UP mode.
For operating instructions, see the respective
items.
④←, →key
Cursor movement keys.
Use to move the digit position when setting a
numerical value in the SET UP mode.The
cursor is positioned on the blinking digit.
⑤↑, ↓key
Numerical value change keys.
Use to change the numerical value in SET UP
mode.
⑥Measurement indicator
Indicates the current mode of measurement;
that is continuous or halted.
During use, the yellow light blinks.
⑦SET UP mode indicator
Yellow light will be turned on at the SET UP
mode.
⑧H.over and L.over displays
If a high-limit or low-limit alarm is set in the
SET UP mode and then the high or low limit is
exceeded, the corresponding display
illuminates.
⑨Temperature display
Displays the temperature of the prism during
measurement.
⑩Measurement value display
Displays measurement or set value digitally.
⑪Scale Display
Displays the measurement values of the
particular scale.
⑫Scale Channel
Displays the measurement channel of the
scale.
Calculation display section front view
Fig.4-3
⑤
②
③
⑥
⑫
⑩
⑪
⑨
⑦
④
①
⑧

9
(2) Rear section (Fig.4-4)
①Power key
Press to turn on the calculation display
section.
②Alarm Output and (External) Scale Switching
Terminal
Use to handle the alarm signal and/or change
the scale (externally).
③RS-232C output terminal
Use to connect the calculation display section
to a personal computer.
④Recorder output terminal
Use to connect the calculation display section
to a recorder.
⑤Detection section - display section connection
terminal:
Connect the DS-2 cable to this terminal.
⑥Power cable
Insert into a 100V AC to 240V AC outlet.
Calculation display section rear view
Fig.4-4
①
②
③
④
⑤
⑥

10
5.Mounting the Detection Section
WARNING
◇Installation: Before performing installation procedures, be sure the display section's power switch is
turned off and the power supply cable is unplugged. Attempting to perform installation while the
instrument is powered on may increase the likelihood of electric shock.
CAUTION
◇Make sure that the piping and equipment are clear of any fluid before mounting the detection section
on the piping and equipment.
5-1. Types of Sample Inlet Unit
There are 4 types of sample inlet unit fittings: straight type, L type, compression fitting and hose
connector.
Straight type: use for mounting within straight sections of a piping system.
L type: use for mounting to the bent, L-shaped section of a piping system.
There are 3 types of connection fittings for attaching the instrument to the piping system: IDF/ISO
clamp union (ferrule), IDF/ISO screw union (screw) and JIS Flange.
Small-diameter fittings: compression fitting (outer diameter: 10mmφ) and hose connector (outer
diameter: 12mmφ) (Fig.5-1).
Fig.5-1
Straight type
L type
Compression Fitting 10mmφ
Hose connector 12mmφ

11
5-2. Mounting the Sample Inlet Unit
Fit the sample inlet unit into the leading section of the detection part, and secure the sample inlet unit
with the attached clamp and O-ring provided.
Fig.5-2
Support of detection section 
Since the detection section weighs 4.1kg, it may not be supported by connection with the sample
inlet unit alone.Therefore, support the detection section, as shown below.If you cannot get the
support, we will supply the following parts.
・Stand (RE-67155)
・Pipe hanger 3S (RE-67157)
・Hanger pin (RE-67156)
For the support bar, prepare a pipe having an outer diameter of 19.0mm and an inner diameter of
16.0 to 17.0mm.
Clamp
O-ring
(silicon or
EPDM)
O-ring
(silicon or EPDM)

12
5-3. Mounting on the Piping (main) (in the case of L type)
Mount the detection section on the piping, observing the flow direction of the fluid to ensure it will hit
the prism surface of the detection section (Fig.5-3).
Fig.5-3
5-4. Mounting on the Piping (main) (in the case of straight type)
When mounting the detection section to the piping, keep it positioned parallel to or below the piping
to ensure the flow of sample passes over the prism.
Mounting the detection section as shown in Fig.5-4 is not advised, as low pressure or flow rate may
prevent the sample from contacting the prism sufficiently, interfering with measurement.
Fig.5-4
5-5. Position of the thermo sensor
There is a built-in thermo sensor near the prism.
As the position of the thermo sensor is marked (Fig.5-5), mount the detection section to keep the
mark upstream in case the sample temperature widely varies.
Fig.5-5
Top
Fluid flow
Fluid flow
Bottom
Mount the sample inlet unit so that the
mark indicating the location of the
temperature sensor is kept upstream of the
sample flow.
Fluid flow

13
6.Mounting the Display Section
WARNING
◇Installation: Before performing installation procedures, be sure the display section's power switch is
turned off and the power supply cable is unplugged. Attempting to perform installation while the
instrument is powered on may increase the risk of electric shock.
It is recommended that the display section is mounted in a control box.
The display section is equipped with a wall-mount handle on the rear face, allowing the part to be mounted
to a wall surface (Fig.6-1).
Do not mount the instrument in a way that hinders access to operate the instrument.
When mounting the display section on a panel, use up to two flat washers to adjust the thickness of the
panel as needed and bolt the display section.
The table assumes panel thicknesses of 1 to 5mm (Table 6-1).
Panel cut dimensions
Fig.6-1
Mounting bolt M6×12
Plain washer
Panel surface
Mounting bolt M6×12
Plain washer
Panel surface
Cap screw M4×8SW, 8pcs
Unit front
182＋1.0
-0
2－φ6.5
224
210＋1.0
-0

14
Fig.6-2
Panel thickness
Plain washer
Schematic
1mm
2pcs
2mm
2pcs
3mm
1pc
4mm
1pc
5mm
0pc
Table 6-1
Hexagon bolt M6×12
Plain washer
Spring washer
1.9
12
1.6
Accessories:
Hexagon bolt···············2
Plain washer···············4
φ11.5

15
7.Connecting the Detection Section to the
Display Section
WARNING
◇Connecting/disconnecting the cable and connector: Before connecting/disconnecting the cable and
connector, be sure the display section's power switch is turned off and the power supply cable is
unplugged. Attempting to connect/disconnect the cable and connector while the instrument is powered
on may increase the risk of electric shock.
mWhen using the display section's terminals, be sure to remove the metal caps, as well as the rubber
caps (Fig.7-1).
After mounting the detection section on the piping, connect it to the display section with the DS-2 cable
(included) (Fig.7-2).
Fig.7-1

16
Fig.7-2
DS-2 cable for connecting the display
and detection sections
Back of the calculation display section
Front of the calculation display section
Detection section

17
8.External Output
WARNING
◇Connecting/disconnecting the cable and terminal: Before connecting/disconnecting the cable and
terminal, be sure the display section's power switch is turned off and the power supply cable is
unplugged. Attempting to connect/disconnect the cable and terminal while the instrument is powered
on may increase the risk of electric shock.
The display section contains three external output ports: a recorder output (4 to 20mA) port, an RS-232C
output port, and an alarm output cable port (Fig.8-1).
Fig.8-1
8-1. Recorder Output(Fig.8-2・Fig.8-3)
Refractive index, Brix or concentration and temperature (0 to 100˚C) are generated as recorder
outputs (4 to 20mA) by the detection section.
Insert the recorder output cable (included) into the port on the rear of the display section.
See "11-3.Setting recorder output" on Page 30 for SET UP mode instructions.
Table 8-1 Lead wire color
Pin number
Cord color
Signal name
Output
1
Red
Refractive Index
(Brix, concentration) +
4 to 20mA
2
Black
Temperature +
4 to 20mA
3
Red & White
(stripe)
Refractive Index
(Brix, concentration) -
4 to 20mA
4
Black & White
(stripe)
Temperature－
4 to 20mA
Fig.8-2
Fig.8-3
47.1mm
50.0mm
※Four terminals (two not shown)
φ14.9
Display section rear panel
Wire number plug
front view
3
2
1
4

18
8-2. RS-232C Output
This unit provides RS-232C outputs for use with a PC via an external output port installed on the rear
panel of the calculation display section.
Use the exclusive connecting cable (option) to collect RS-232C outputs.
Keep the calculation display section and PC at most 15m apart.
①Dedicated cable specifications (Fig.8-4 and Fig.8-5)
Table 8-2 Lead wire color
Calculation display section
D－Sub connector (PC side)
Pin
number
Cord color
Signal
name
Pin
number
Cord color
Signal
name
1
Red
RXD
2
Red & White
(stripe)
RXD
2
Red & White
(stripe)
TXD
3
Red
TXD
3
Black
GND
5
Black
GND
7
－
RTS
8
－
CTS
Fig.8-4
Fig.8-5
②Communications parameters
Baud rate : 9600bps
Data length : 8bit
Parity : ODD
Stop bits : 1bit
③Transmitted data format
a.aaaaa,bb.bbb,cc.ccc,dd.ddd,eeeeee,fff.ff,g
a.aaaaa : Refractive Index
bb.bbb : Brix 1
cc.ccc : Brix 2
dd.ddd : Brix 3
eeeeee : Concentration (Conc)
fff.ff : Temperature
g : CH (0 to 4)
g
Scale
0
nD（Refractive Index ）
1
Brix 1
2
Brix 2
3
Brix 3
4
Conc（Concentration ）
φ14.9
D-Sub 9P Connector
43.2mm
Wire number plug
front view
4
1
2
3

19
8-3. Alarm Output (high- and low-limiter output)
The alarm output functions based on the established range of acceptable measurement values.
When a value is detected that falls outside of the acceptable range alarm output is transmitted from
the detection section.
The high-limiter and low-limiter output circuit has a photocoupler with a transistor open collector in
the final stage. See the diagram on the following page before using the limiter circuit.
①Dedicated cable (option) specifications (Fig.8-6 and Fig.8-7)
Pin numbers 1 to 3 are used for the alarm output.
Pin numbers 4 to 6 are used for switching the scales. Refer to pg. 20, "8-4Switching the Scale
(externally)."
Table 8-3 Lead wire color
Pin number
Cord color
Signal name
1
Brown
High-limiter output
＋
2
Red
Low-limiter output
＋
3
Black
Limiter Com
－
4
Yellow
External Switch
B0
5
White
External Switch
B1
6
Green
External Switch Com
－
Fig.8-6
Fig.8-7
②High- and low-limiter output typical applications
The high-limiter and low-limiter output circuit has a photocoupler with a transistor open collector in
the final stage. Before using the limiter circuit, see Fig.8-8, Fig.8-9 and Fig.8-10.
a. Drive a relay
Fig.8-8
b. Turn on a LED
Fig.8-9
29.8mm
φ12.6
Photocoupler
Relay coil
V+
Photocoupler
LDE
V+
R
Wire number plug
front view
4
1
2
5
6
3
50.0mm