Riken Keiki OHC-800 User manual

PT3E-04914
Explosion-Proof Calorimeter
OHC-800
Operating Manual

1 Important Notices on Safety 1-1. Danger cases
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Thank you for choosing our explosion-proof calorimeter OHC-800.
This manual explains how to use the calorimeter and its specifications. It contains information required for
using the calorimeter properly. Not only the first-time users but also the users who have already used the
product must read and understand the operating manual to enhance the knowledge and experience before
using the calorimeter.
Throughout this manual, the following indications are used to ensure safe and effective work.
DANGER This message indicates that improper handling may cause death or serious
damage on health or assets.
WARNING This message indicates that improper handling may cause serious damage on
health or assets.
CAUTION This message indicates that improper handling may cause minor damage on
health or assets.
NOTE This message indicates advice on handling.
Note) MODBUS is registered trademarks of Schneider automation inc.

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<Contents>
1. Important Notices on Safety ......................................................................................................................................5
1-1. Danger cases ...................................................................................................................................................5
1-2. Warning cases..................................................................................................................................................6
1-3. Precautions ......................................................................................................................................................7
1-4. Method of confirmation for Standards and Explosion proof specification .........................................................7
1-5. Information about explosion-proof performance (Japanese explosion-proof spec.) .........................................8
1-5-1. About OHC-800 .......................................................................................................................................8
1-5-2. Technical data..........................................................................................................................................8
1-5-3. System configuration for use in hazardous location ................................................................................9
1-6. Information about explosion-proof performance (Overseas explosion-proof spec.) .........................................10
1-6-1. About OHC-800 .......................................................................................................................................10
1-6-2. Technical data..........................................................................................................................................10
1-6-3. System configuration for use in hazardous location ................................................................................11
1-6-4. Notice on safety.......................................................................................................................................12
2. Product Components.................................................................................................................................................15
2-1. Purpose of use and features of this product .....................................................................................................15
2-2. Main unit and standard accessories .................................................................................................................16
2-3. Names of internal product components............................................................................................................17
2-4. Names and functions of display........................................................................................................................18
3. How to Install Calorimeter .........................................................................................................................................19
3-1. Precautions on installation site .........................................................................................................................19
3-2. Installation procedure and required maintenance space ..................................................................................20
3-3. How to connect wire .........................................................................................................................................21
3-3-1. Description of terminal block....................................................................................................................21
3-3-2. Recommended cables.............................................................................................................................23
3-3-3. How to lead in and connect cables ..........................................................................................................24
3-3-4. Protective grounding................................................................................................................................26
3-3-5. Precautions on electrical work .................................................................................................................27
3-4. How to tube ......................................................................................................................................................30
3-4-1. Sampling device ......................................................................................................................................30
3-4-2. Recommended external tubing system ...................................................................................................31
3-4-3. Precautions on tubing work .....................................................................................................................32
4. How to Operate in MEASURING MODE...................................................................................................................33
4-1. From display just after power-on to measurement start....................................................................................33
4-2. How to switch display screens..........................................................................................................................35
4-3. Switching to other mode...................................................................................................................................36
4-4. Self-diagnostic function ....................................................................................................................................37
4-5. Operations of contacts, display, and signal output after recovery to normal state ............................................38
5. How to Operate in Check Mode ................................................................................................................................39
5-1. Menu items of CHECK MODE..........................................................................................................................40
5-2. Items and details ..............................................................................................................................................41
5-2-1. Check of optical sensor unit state (OPTICAL SENSOR UNIT CONDITION) ........................................... 41
5-2-2. Check of sonic sensor unit state (SONIC SENSOR UNIT CONDITION).................................................42
5-2-3. Check of main controller state (MAIN CONTROLLER CONDITION).......................................................42
5-2-4. Check of measuring conditions for calorific value (CALORIFIC VALUE PARAMETER) ..........................43
5-2-5. Check of measuring conditions for density (DENSITY PARAMETER) ....................................................43
5-2-6. Check of 4 - 20 mA settings (4 - 20 mA PARAMETER) ...........................................................................43
5-2-7. Check of pressure sensor output (PRESSURE SENSOR READINGS) ..................................................44
5-2-8. Check of temperature sensor output (TEMPERATURE SENSOR READINGS)......................................44
5-2-9. Check of calorific value calculation settings (CALCULATION FACTOR (CALORIFIC VALUE)) ..............45
5-2-10. Check of density calculation settings (CALCULATION FACTOR (DENSITY)).......................................45
5-2-11. Check of Opt-Sonic calculation process (OPT-SONIC READINGS)......................................................46
5-2-12. Check of display and contact settings (DISP. & CONTACT PARAMETER) ...........................................46
5-2-13. Latching reset for display and contact (LATCHING RESET (DISP. & CONTACT))................................47
6. How to Operate in SETUP MODE.............................................................................................................................48
6-1. SETUP MODE items ........................................................................................................................................50
6-2. Items and details ..............................................................................................................................................51
6-2-1. Setting of calorific value calculation conditions (CALCULATION FACTOR (CALORIFIC VALUE)) .........51
6-2-2. Setting of density calculation conditions (CALCULATION FACTOR (DENSITY))....................................52

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6-2-3. 4 – 20 mA condition settings (4 – 20 mA SETTINGS)..............................................................................53
6-2-4. 4 – 20 mA output adjustment (4 – 20 mA ADJUSTMENT).......................................................................54
6-2-5. 4 – 20 mA output test (4 – 20 mA TEST) .................................................................................................55
6-2-6. Reference calibration (REF. CALIBRATION) ...........................................................................................56
6-2-7. Offset (OFFSET ADJUSTMENT).............................................................................................................57
6-2-8. Display and contact operation settings (DISP. & CONTACT SETTINGS)................................................58
6-2-9. LCD display settings (LCD DISPLAY SETTINGS)...................................................................................59
6-2-10. RS-485 (MODBUS) communication settings (RS-485(MODBUS) SETTINGS).....................................60
6-2-11. Change of energized contact settings (CONTACT SETTINGS).............................................................61
6-2-12. Check the contact operation (CONTACT TEST)....................................................................................61
6-2-13. Password change (PASSWORD SETUP (SETUP MODE)) ..................................................................62
6-2-14. Log data download (IrDA COMMUNICATION) ......................................................................................62
7. Maintenance 63
7-1. Maintenance intervals and items ......................................................................................................................63
7-1-1. Daily maintenance ...................................................................................................................................63
7-1-2. Monthly regular maintenance ..................................................................................................................64
7-1-3. Biannual regular maintenance .................................................................................................................65
7-2. Recommended regular replacement parts .......................................................................................................66
8. Storage, Relocation, and Disposal ............................................................................................................................67
8-1. Procedures to store the calorimeter or leave it for a long time .........................................................................67
8-2. Procedures to relocate the calorimeter or use it again .....................................................................................67
8-3. Disposal of products .........................................................................................................................................68
9. Troubleshooting.........................................................................................................................................................69
9-1. <FAILURE> ......................................................................................................................................................69
9-2. <OUT OF SPECIFICATION>............................................................................................................................72
9-3. <MAINTENANCE REQUIRED> .......................................................................................................................74
9-4. <FUNCTION CHECK> .....................................................................................................................................75
9-5. CAUTION screen .............................................................................................................................................76
9-6. Others...............................................................................................................................................................77
9-7. If not applicable to display ................................................................................................................................78
10. Product Specifications.............................................................................................................................................79
10-1. Product specifications.....................................................................................................................................79
10-2. Principle of this product ..................................................................................................................................80
10-2-1. Opt-Sonic calculation (calorific value)....................................................................................................80
10-2-2. Opt-Sonic calculation (specific gravity) ..................................................................................................82
10-2-3. Principle of optical sensor......................................................................................................................84
10-2-4. Principle of sonic sensor........................................................................................................................85
11. Definition of Terms...................................................................................................................................................86
11-1. Definition of terms used in operating manual..................................................................................................86
11-2. Definition of terms used in "Measuring gas specification sheet".....................................................................87

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1
Important Notices on
Safety
1-1. Danger cases
DANGER
<About explosion-proof>
Satisfy the following installtaion requirements of the calorimeter.
Do not open the lid during operation.
Turn off the power of the calorimeter before replacing the fuse.
(Fuse specifications: 250 V, 1 A, Φ5 x 20 mm, time lag type)
Do not disassemble/modify the calorimeter, or change the settings if not necessary.
Contact RIKEN KEIKI for information on readjustment including gas calibration and parts
replacement.
Do not replace parts at your sole discretion but contact RIKEN KEIKI if the transparent window has a
crack or the explosion-proof joint surface is abnormal, or the clamping screw or bolt is changed, lost
etc.
Never fail to perform a regular maintenance.
Use appropriate cables to wire.
Use ring terminals etc. for electrical connections and ensure safe connection without any slack or
tangle.
Use ring terminals to connect the grounding terminal with the ground and use the grounding wire
with cross-sectional area of 4 mm2or more for the external grounding terminal.
The transparent window is made of polycarbonate resin. Be careful that it may be damaged by an
atmosphere of toluene, benzene, ammonia, aromatic hydrocarbon etc.
Do not repair the explosion-proof joint surface.
Use a control key (magnet) specified by RIKEN KEIKI.
Gas conditions (Explosion protection conditions)
Maximum flow rate Measuring gas (GAS IN) 1 L/min
Reference gas (REF IN) 0.5 L/min
Pressure 80 to 110 kPa for all of GAS IN, REF IN, and OUT
Temperature -20 to 57°C for all of GAS IN, REF IN, and OUT(Japanese explosion-proof spec.)
-20 to 60°C for all of GAS IN, REF IN, and OUT(Overseas explosion-proof spec.)

1 Important Notices on Safety 1-2. Warning cases
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1-2. Warning cases
WARNING
<About explosion-proof>
Do not open the front lid of the OHC-800 if the existence of an explosive atmosphere is suspected.
WARNING
<Power>
Before turning on the calorimeter, always check that the voltage is properly applied. Do not use an
unstable power supply because it may cause malfunctions.
The settings in the calorimeter vary depending on the AC and DC power specifications (See the
figure below).
The calorimeter is damaged if incorrect power is supplied to incorrect settings.
Check the specifications and supply the correct power.
Power terminal unit with Power terminal unit with
AC specifications DC specifications

1 Important Notices on Safety 1-3. Precautions
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1-3. Precautions
1-4. Method of confirmation for Standards and
Explosion proof specification
This instrument has some specification depends on standard and explosion proof certificate. Please
confirm the detector specification before using. Please refer Declaration of Conformity that is at the end of
this manual if you have CE marking type.
You can confirm instrument specification to see name plate as follows.
ATEX/IECEx, CE marking type name plate TIIS type name plate
CAUTION
Do not use a transceiver near the calorimeter.
Radio wave from a transceiver near the calorimeter or its cables may disturb indication reading. If a
transceiver is used, it must be used in a place where it disturbs nothing.
To restart the calorimeter, wait for five seconds or more before doing it.
Restarting the calorimeter within five seconds may cause errors.
Do not disassemble/modify the calorimeter, or change the settings if not necessary.
Disassembling/modifying the calorimeter will invalidate the warranty of the performance. Changing
the settings without understanding the specifications may cause malfunctions. Please use the
calorimeter properly in accordance with the operating manual.
Avoid applying organic solvents and others to the window plate for a long time.
The window plate material is a polycarbonate resin. When organic solvents (liquid or
highly-concentrated vapor) and others are applied to the plate for a long time, its color and shape
may be changed.
CE marking
Ex marking
TIIS certificate
Ⅱ
2G Ex db
Ⅱ
B
+
H
2
T4 Gb

1 Important Notices on Safety 1-5. Information about explosion-proof performance (Japanese explosion-proof spec.)
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1-5. Information about explosion-proof performance
(Japanese explosion-proof spec.)
1-5-1. About OHC-800
The OHC-800 is an explosion-proof calorimeter. According to measured calorific values, 4 - 20 mA signals
and digital signals are output.
The calorimeter is used for the purposes of calorific value recording and device control by conntecting it to a
recorder or a programmable controller.
The calorimeter has three contact outputs and these are activated by malfunction etc. of the device.
1-5-2. Technical data
Explosion-proof structure Flame-proof enclosures
Certificate number (TIIS) No. TC20344
Explosion-proof class Ex dⅡB+H2T4
Ambient temperature -20 to 57°C
Rating Power supply 100 VAC/110 mA - 240 VAC/70 mA, 50/60 Hz,
24 VDC/190 mA
Analog signal
output
24 VDC/0 - 22 mA
Digital signal
input-output
RS-485 (MODBUS)
Contact output
(Contact capacity)
240 VAC/20 W (Load resistance)
30 VDC/2 A (Load resistance)
30 VDC/2 A (Load resistance)
Applied standard JNIOSH－TR－NO.43 (2008)
Manufacturer: RIKEN KEIKI CO., LTD.
2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744 Japan
Web site: https://www.rikenkeiki.co.jp/

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1-5-3. System configuration for use in hazardous location
The OHC-800 has a flame-proof enclosure (Explosion-proof class: Ex dⅡB+H2 T4) and can be used in a
Class 1 location. However, if the power source and display instrument etc. connected to it do not have an
explosion-proof structure, install it in a non-hazardous area.
Hazardous area Non-hazardous area
Calorimeter (OHC-800)
AC/DC power source
Display instrument
Display instrument
Display instrument

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1-6. Information about explosion-proof performance
(Overseas explosion-proof spec.)
1-6-1. About OHC-800
This product is a sample draw type fixed Calorimeter.
2 power inputs, AC and DC, are available on the Calorimeter.
1-6-2. Technical data
(Name) :CALORIMETER
(Type) :OHC-800
(Protection Method) : Flameproof enclosure “d”
(Certificate numbers)IECEx DEK 12.0058X
DEKRA 12ATEX0187 X
(Group) : II
(Category) : 2G
(Type of Protection and Marking code) : Ex db IIB+H2T4
(Equipment Protection Level) : Gb
(Ambient Temperature) : -20℃~ 60℃
(Electrical Data):
Supply voltage : 100VAC/95mA～240VAC/70mA 50 /60 Hz
or 24VDC/190mA
Contact output : 30VDC/2A
Contact output : 240VAC/1A
Output signal : 4-20mA (24 VDC/20mA)
Digital Communication :RS485
(Applicable Standard) EN IEC 60079-0:2018, EN 60079-1:2014
IEC 60079-0:2017, IEC 60079-1:2014-6

1 Important Notices on Safety 1-6. Information about explosion-proof performance (Overseas explosion-proof spec.)
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1-6-3. System configuration for use in hazardous location
CVVSCable
Sig+
Sig‐
Sig+
Sig‐
Indicator etc.
ACPower/DCPower
L/+
N/‐
PE
CaloriMeter (OHC‐800)
Hazardous Location Nonhazardous Location
InstallationDiagram
RLY RLY
CVVSCable
RLY RLY
RLY RLY
CVVSCable
RS485 RS485
Indicator etc.
Indicator etc.

1 Important Notices on Safety 1-6. Information about explosion-proof performance (Overseas explosion-proof spec.)
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1-6-4. Notice on safety
WARNING
・Do not open when an explosive atmosphere is present.
Caution
・Do not open the cover while in operation.
・Do not take apart, remodel and change the instrument.
・Contact the nearest Riken Keiki’s agents or Riken Keiki to perform adjustment, including the gas
calibration, and parts replacement etc.
・Contact the nearest Riken Keiki’s agents or Riken Keiki if any abnormalities are found.
・Make sure to perform a regular check.
・Make sure to use suitable cables.
・Do not repair the flame-proof composition surface.
・All bolt with the hexagon socket must use the stainless steel material of property
class "A2-70".
・The internal and external ground connection shall be made with a cable lug and be
secured by additional means to prevent twisting.
・At the internal ground connection the cable lug shall be installed between
the washer and the toothed lock washer.
・Gas conditions
Composition
IIC gases other than H2cannot be used.
MaxFlow
Measurement gas:1L/min Reference Gas:0.5L/min
Pressure range
Measurement Gas Reference Gas Out Gas : 80～110kPa
Temperature
Measurement Gas Reference Gas Out Gas :-20～60℃
・In case oxygen presents in the sampling gas which is supplied into OHC-800 and emitted
from OHC-800, contents of oxygen should be lower than that normally present in air.
・The sampling gas which is supplied into OHC-800 and emitted from OHC-800 should not be within
the explosive limits continuously for long period or frequency.
・Power on the measuring system after pipings in the enclosure are purged with process gas.
Also, power off the measuring system while pipings in the enclosure are purged with process gas.
・Periodic maintenance service shall be performed to check if there is no failure of the gas containment.

1 Important Notices on Safety 1-6. Information about explosion-proof performance (Overseas explosion-proof spec.)
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Earth terminal
Cable gland

1 Important Notices on Safety 1-6. Information about explosion-proof performance (Overseas explosion-proof spec.)
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Please install a cable gland into OHC-800 according to the following figure.
Please tighten a bolt of a cable gland at 40N･m or more
Special conditions for safe use
・Repair of the flameproof joints is not allowed.
・Fasteners have property class A2-70.

2 Product Components 2-1. Purpose of use and features of this product
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2
Product Components
2-1. Purpose of use and features of this product
This calorimeter is an explosion-proof calorimeter in a flame-proof enclosure designed for continuous,
fast-response measurement of the "Calorific value," "Density," and "WOBBE index" of various fuel gases
such as natural gas, coke oven gas, blast furnace gas, converter gas, biomass gas, and biogas.
The types of fuel gases that can be measured depend on the specifications. For information on the types
of gases that can be measured by the product, check the "Measuring gas specification sheet" provided
with it.
The calorimeter measures the speeds of "light" and "sound" that travel through the measuring gas by
using an "optical sensor" and a "sonic sensor" and applying the Opt-Sonic calculation processing* to the
measuring result. This enables the high-accuracy measurement of "Calorific value" and "Density" of fuel
gases containing interference gases such as nitrogen and carbon dioxide.
NOTE
For information on Opt-Sonic calculation, see Section 10.2, "Principle of this product."
Opt-Sonic calculation is a coined word by RIKEN KEIKI.
The calorimeter can be used with minimum equipment even under constraint conditions with its high
evironmental resistance.
The calorimeter, having an advanced self-monitoring/diagnostic function compliant with NAMUR NE107
(self-monitoring/diagnostic of field devices), offers functions for performing real-time status monitoring for
devices and informing abnormal statuses and maintenance requests with LCD display and contact
output.
The calorimeter has a log data auto-save function that records the history of "operation statuses" and
"self-diagnostic results" for a year or longer. Furthermore, another function provides outputting the log
data via IrDA communication, which can be used for high-quality maintenance/follow-up services.
(Optional services)
The calorimeter forms a "complete stand-alone unit structure" that consists of standardized units. Even if
any malfunction occurs, quick repair and recovery can be achieved just by replacing a faulty unit on site.

2 Product Components 2-2. Main unit and standard accessories
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2-2. Main unit and standard accessories
<Main unit> (including cable glands)
<Standard accessories>
Operating manual
Measuring gas specification sheet
Dedicated control key (magnet)
Hex key wrench (2 mm and 6 mm, one each)
Fuse (250V 1A Φ5 x 20 mm，two)
Cable gland
CAUTION
Use the supplied dedicated magnet control key to operate the calorimeter. If products other than
these accessories are used, key operations cannot be accepted properly.
The magnet control key is made of an extremely strong magnet. Keep it away from a credit card,
ID card, or other magnetic product because stored data may be destroyed.

2 Product Components 2-3. Names of internal product components
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2-3. Names of internal product components
Name Functions
Optical sensor unit Measures the speed of light that travels through the measuring gas by
capturing the refractive index. In addition, this unit monitors the flow rates of
the measuring gas and REF gas.
Sonic sensor unit Measures the speed of sound that travels through the measuring gas.
Power terminal unit Supplies power to other units.
This unit relays signals between units, performs contact output, and outputs
4 - 20 mA analog signals and RS-485 (MODBUS) communication signals.
Main controller Calculates and displays the "Calorific value," "Density," and "WOBBE index"
based on data received from the optical sensor unit and the sonic sensor
unit. Also converts the units of "Calorific value" and "Density."
Checks the operation statuses of other units to ensure normal measurement
and output.
Main controller Power terminal unit
Sonic sensor unit
Optical sensor unit

2 Product Components 2-4. Names and functions of display
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2-4. Names and functions of display
MODE/ESC key Switches MEASURING MODE to other mode.
Used to stop processing.
POWER lamp (green) Lights up at power-on.
EV1 lamp (orange) Lights up in conjunction with Contact Output 1.
EV2 lamp (red) Lights up in conjunction with Contact Output 2.
EV3 lamp (green) Lights up in conjunction with Contact Output 3.
▲key Moves the cursor or increases the setting value.
DISP/SET key Switches the display content in MEASURING MODE.
Confirms processing etc.
LCD display Displays measurement values, operation statuses, or other
information.
IrDA communication port The IrDA communication port for maintenance. Reads event log or
daily log information recorded on the product.
▼key Moves the cursor or decreases the setting value.
Use the attached magnet control key to operate all the switches
described in the above table. Holding the magnet control key
over the switch marks for a few seconds will start the switches.
The description of "press the XXX switch" in this operating manual
means holding the magnet control key over the marks and ▼▲.
Control key (magnet)
Ⅱ2G Ex dbⅡB+H2 T4 Gb

3 How to Install Calorimeter 3-1. Precautions on installation site
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3
How to Install Calorimeter
3-1. Precautions on installation site
Use the calorimeter in combination with a sampling device specified by RIKEN KEIKI (or an equivalent
cubicle). Do not install this product in any of the following locations.
(1) Place where the calorimeter is exposed to oil,
chemicals etc.
(2) Place with vibrations
(3) Place where radio wave or noise is generated (4) Place where the calorimeter may drop or
receive strong shock
(5) Place exceeding the operating temperature
range
Place where the calorimeter is exposed to direct
sunlight or radiant heat
(6) Place where maintenance of the calorimeter
cannot be performed
Place where handling of the calorimeter involves
dangers

3 How to Install Calorimeter 3-2. Installation procedure and required maintenance space
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3-2. Installation procedure and required maintenance
space
Install the OHC-800 and the
sampling device on the surface of a
robust wall or a freestanding rack
etc. using bolts.
Before installation, a maintenance
space shown in the figure on the
right must be secured.
Be sure to secure this space during
construction planning or installation.
Maintenance space (Unit: mm)
CAUTION
Do not drop or give strong shock to the calorimeter during transportation or installation.
Otherwise, the calorimeter may be damaged, or the explosion-proof performance may be lost.
When installing the calorimeter on a freestanding rack (fixed type), fix the freestanding rack with
anchor bolts.
If the calorimeter is to be fixed on the wall, install it properly where it can hold its weight.
When performing construction work, prevent dust from entering the inside of the calorimeter.