Michell Instruments S8000 User manual

S8000
Chilled Mirror Hygrometer
User’s Manual
97488 Issue 4
August 2018

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© 2018 Michell Instruments
This document is the property of Michell Instruments Ltd. and may not be copied or
otherwise reproduced, communicated in any way to third parties, nor stored in any Data
Processing System without the express written authorization of Michell Instruments Ltd.
S8000
For Michell Instruments' contact information please go to
www.michell.com

S8000 User’s Manual
iv 97488 Issue 4, August 2018
1 INTRODUCTION ................................................................................................1
1.1 Operating Principle ............................................................................................. 2
2 INSTALLATION ..................................................................................................3
2.1 Safety................................................................................................................ 3
2.2 Unpacking the Instrument................................................................................... 3
2.3 Operating Requirements ..................................................................................... 5
2.3.1 Environmental Requirements ......................................................................... 5
2.3.2 Electrical Requirements ................................................................................. 5
2.4 Exterior Layout................................................................................................... 5
2.5 Rear Panel Connections (All Versions) .................................................................. 8
2.5.1 Power Supply Input....................................................................................... 9
2.5.2 Analog Output Connections.......................................................................... 10
2.5.3 Alarm Output Connections ........................................................................... 11
2.5.4 Remote PRT Probe (Optional) ..................................................................... 13
2.5.5 4-Wire PRT Output (Optional) ...................................................................... 14
2.5.6 USB Communications Port Connector............................................................ 14
2.5.7 Ethernet Port (Optional) .............................................................................. 15
2.5.8 RS232/485 Port (Optional)........................................................................... 15
2.5.9 Connection of Gas Supplies.......................................................................... 17
2.6 Internal Sample Pump (Optional)....................................................................... 19
2.7 Conversion of S8000 to Rack Mount .................................................................. 20
3 OPERATION ....................................................................................................21
3.1 General Operational Information........................................................................ 21
3.2 Instrument Display ........................................................................................... 22
3.2.1 Main Screen................................................................................................ 23
3.2.2 Customizable Readouts................................................................................ 24
3.2.3 Operational Status Display........................................................................... 24
3.2.4 Setup Menu Screen ..................................................................................... 25
3.2.5 Menu Structure .......................................................................................... 27
3.2.6 DCC ........................................................................................................... 28
3.2.7 LOGGING ................................................................................................... 29
3.2.8 OUTPUTS ................................................................................................... 31
3.2.9 ALARM ....................................................................................................... 31
3.2.10 DISPLAY .................................................................................................... 32
3.2.11 CLOCK ....................................................................................................... 33
3.2.12 ABOUT (Network Settings)........................................................................... 33
3.3 Operational Functions ....................................................................................... 34
3.3.1 Operating Cycle .......................................................................................... 34
3.4 Operating Guide ............................................................................................... 35
3.4.1 DCC - Dynamic Contamination Control.......................................................... 35
3.4.2 MAXCOOL Function ..................................................................................... 36
3.4.3 Pressure Compensation ............................................................................... 36
Contents
Safety ................................................................................................................................ix
Electrical Safety ...........................................................................................................ix
Pressure Safety............................................................................................................ix
Toxic Materials .............................................................................................................ix
Repair and Maintenance ...............................................................................................ix
Calibration...................................................................................................................ix
Safety Conformity ........................................................................................................ix
Abbreviations...................................................................................................................... x
Warnings ............................................................................................................................ x

S8000 User’s Manual
Michell Instruments v
3.4.4 Data Logging .............................................................................................. 36
3.4.5 Frost Assurance System Technology (FAST) .................................................. 37
3.4.6 STANDBY Mode........................................................................................... 37
4 APPLICATION SOFTWARE ................................................................................38
4.1 Installation....................................................................................................... 38
4.2 Establishing Communications ............................................................................ 38
4.2.1 USB Communication.................................................................................... 39
4.2.2 RS232/485 Communication.......................................................................... 40
4.2.3 Ethernet Communication ............................................................................. 40
4.3 Data Acquisition or Edit Variables Mode.............................................................. 41
4.3.1 Data Acquisition.......................................................................................... 42
4.3.2 Variable Edit ............................................................................................... 44
5 MAINTENANCE ................................................................................................46
5.1 Safety.............................................................................................................. 46
5.2 Fuse Replacement ........................................................................................... 47
5.3 Sensor Mirror Cleaning...................................................................................... 48
5.3.1 Releasing optics window ............................................................................. 49
5.3.2 Fitting the Microscope (Optional).................................................................. 50
6 GOOD MEASUREMENT PRACTICE .....................................................................51
6.1 Sampling Hints ................................................................................................. 52
7 CALIBRATION..................................................................................................55
7.1 Traceability ...................................................................................................... 55
8 PREPARATION FOR SHIPPING ..........................................................................56

S8000 User’s Manual
vi 97488 Issue 4, August 2018
Tables
Table 1 Front Panel Controls and Indicators ..............................................................6
Table 2 Rear Panel Controls and Indicators ...............................................................8
Table 3 Main Screen Description............................................................................. 23
Table 4 Operational Status Display ........................................................................ 24
Table 5 DCC Parameters ........................................................................................ 28
Table 6 Logging Parameters...................................................................................29
Table 7 SD Card Status Indicators .......................................................................... 30
Table 8 Outputs Parameters................................................................................... 31
Table 9 Alarm Parameters ...................................................................................... 31
Table 10 Display Parameters....................................................................................32
Table 11 Clock Parameters....................................................................................... 33
Table 12 Network Parameters .................................................................................. 33
Table 13 Data Acquisition Control Description ........................................................... 42
Table 14 Graph Control Description .......................................................................... 43
Table 15 Status Bar Description ............................................................................... 43
Table 16 Modbus Holding Register Map .................................................................... 69
Table 17 Register Configuration A ............................................................................ 70
Table 18 Register Configuration B1........................................................................... 70
Table 19 Register Configuration B2........................................................................... 70
Table 20 Register Configuration D Status Word ......................................................... 71
Table 21 Register Configuration E Units .................................................................... 71
Table 22 Register Configuration F Display Setting A ................................................... 71
Table 23 Register Configuration F Display Setting B ................................................... 72
Table 24 Register Configuration H ............................................................................ 72
Table 25 Register Configuration J ............................................................................. 72
Table 26 Register Configuration K ............................................................................ 72
Table 27 Register Configuration L............................................................................. 73
Table 28 Register Configuration M............................................................................ 73
Table 29 Register Configuration N ............................................................................ 73
Table 30 Register Configuration P............................................................................. 74

S8000 User’s Manual
Michell Instruments vii
Figures
Figure 1 S8000........................................................................................................1
Figure 2 Operating Principle .....................................................................................2
Figure 3 S8000 Packing............................................................................................3
Figure 4 Front Panel ................................................................................................6
Figure 5 Rear Panel .................................................................................................7
Figure 6 Power Supply Input ....................................................................................9
Figure 7 Analog Output Connectors ........................................................................10
Figure 8 Alarm Output Connectors..........................................................................12
Figure 9 Remote PRT Connection............................................................................13
Figure 10 Internal PRT Output (Optional)..................................................................14
Figure 11 USB Port Connection.................................................................................14
Figure 12 Ethernet Port (Optional)............................................................................15
Figure 13 RS232/485 Port (Optional) ........................................................................15
Figure 14 Gas Connections.......................................................................................17
Figure 15 Gas Connections when Pump is Fitted........................................................19
Figure 16 Rack Fixing Method ..................................................................................20
Figure 17 Initialising Overlay Screen.........................................................................22
Figure 18 Main Screen .............................................................................................22
Figure 19 Main Screen Layout ..................................................................................23
Figure 20 Setup Menu Screen ..................................................................................25
Figure 21 Virtual Keyboard ......................................................................................26
Figure 22 Menu Structure ........................................................................................27
Figure 23 DCC Screen..............................................................................................28
Figure 24 Logging Screen ........................................................................................29
Figure 25 Outputs Screen ........................................................................................31
Figure 26 Alarm Screen ...........................................................................................31
Figure 27 Display Screen .........................................................................................32
Figure 28 Clock Screen ............................................................................................33
Figure 29 Network Settings Screen ...........................................................................33
Figure 30 Typical Operating Cycle.............................................................................34
Figure 31 Communications Setup Screen ..................................................................38
Figure 32 Windows Device Manager Screen ..............................................................39
Figure 33 Network Settings Screen ...........................................................................40
Figure 34 Options Screen.........................................................................................41
Figure 35 Data Acquisition Screen ............................................................................42
Figure 36 Variables Editor Screen .............................................................................45
Figure 37 Power Supply Fuse Replacement ...............................................................47
Figure 38 Sensor Mirror Cleaning..............................................................................48
Figure 39 Releasing Optics Window ..........................................................................49
Figure 40 Fitting the Microscope...............................................................................50
Figure 41 Typical Calibration Certificate.....................................................................55
Figure 42 Instrument Packing Details........................................................................56
Figure 43 Select Format...........................................................................................62
Figure 44 Set Format Properties ...............................................................................62
Figure 45 Format Disc .............................................................................................62
Figure 46 Modbus Connection ..................................................................................67

S8000 User’s Manual
viii 97488 Issue 4, August 2018
Appendices
Appendix A Technical Specifications.............................................................................. 58
A.1 Dimensions ................................................................................. 60
Appendix B Formatting SD cards ................................................................................. 62
Appendix C Calculations .............................................................................................. 64
C.1 Water Content............................................................................. 64
C.2 Temperature - Dew Point ........................................................... 64
C.3 °C to °F Calculation ....................................................................64
C.4 % RH Calculation ........................................................................64
C.5 Conversion of bara to psia and kPa ..............................................65
Appendix D Modbus RTU Communications .................................................................... 67
D.1 Introduction ............................................................................... 67
D.2 Basic Modbus Operation .............................................................. 67
D.3 Modbus RTU Connections and Protocol.......................................... 68
D.4 Register Map .............................................................................. 68
Appendix E Default Values........................................................................................... 76
Appendix F Quality, Recycling & Warranty Information................................................... 78
Appendix G Return Document & Decontamination Declaration........................................ 80

S8000 User’s Manual
Michell Instruments ix
Safety
The manufacturer has designed this equipment to be safe when operated using the procedures
detailed in this manual. The user must not use this equipment for any other purpose than that
stated. Do not apply values greater than the maximum value stated.
This manual contains operating and safety instructions, which must be followed to ensure the safe
operation and to maintain the equipment in a safe condition. The safety instructions are either
warnings or cautions issued to protect the user and the equipment from injury or damage. Use
qualified personnel and good engineering practice for all procedures in this manual.
Electrical Safety
The instrument is designed to be completely safe when used with options and accessories supplied
by the manufacturer for use with the instrument. The input power supply voltage limits are 85 to
264 V AC, 47/63 Hz. Refer to Appendix A - Technical Specifications.
Pressure Safety
!
Before pressurizing, the user must ensure through appropriate
protective measures that the system or the device will not be over-
pressurized. When working with the instrument and pressurized
gases safety glasses should be worn.
DO NOT permit pressures greater than the safe working pressure to be applied to the instrument.
The specified maximum safe working pressure is 1 barg (14.5 psig) for the low pressure version,
or 20 barg (290 psig) for the high pressure version. This instrument is not designed to accept gas
pressures higher than the specified maximum working pressure.
Application of gas pressures higher than the specified maximum will result in potential damage
and may render the instrument unsafe and in a condition of incorrect functionality. Only personnel
trained in the safe handling of high pressure gases should be allowed to operate this instrument.
Refer to Appendix A - Technical Specifications in this manual.
Toxic Materials
The use of hazardous materials in the construction of this instrument has been minimized. During
normal operation, it is not possible for the user to come into contact with any hazardous substance,
which might be employed in the construction of the instrument. Care should, however, be exercised
during maintenance and the disposal of certain parts.
Repair and Maintenance
The instrument must be maintained either by the manufacturer or an accredited service agent. Refer
to www.michell.com for details of Michell instruments' worldwide offices contact information.
Calibration
The recommended calibration interval for the S8000 is one year, unless otherwise specified by Michell
Instruments Ltd. The instrument should be returned to the manufacturer, Michell Instruments, or one
of their accredited service agents for re-calibration (go to www.michell.com for contact information).
Safety Conformity
This product meets the essential protection requirements of the relevant EU directives. Refer to
Appendix A - Technical Specifications - for details.

S8000 User’s Manual
x97488 Issue 4, August 2018
Abbreviations
The following abbreviations are used in this manual:
DCC Dynamic Contamination Correction
FAST Frost Assurance System Technology
MAXCOOL Maximum Sensor Cooling
AC alternating current
atm pressure unit (atmosphere)
barg pressure unit (=100 kP or 0.987 atm) gauge
bara pressure unit (absolute)
°C degrees Celsius
°F degrees Fahrenheit
COM common
dp dew point
EU European Union
g/Kg grams per kilogram
g/m3grams per cubic meter
HMI Human Machine Interface
Hz Hertz
IEC International Electrotechnical Commission
Nl/min normal liters per minute
lb pound
mA milliampere
max maximum
min minute(s)
mV millivolt(s)
N/C normally closed
N/O normally open
No number
ppmVparts per million (by volume)
ppmWparts per million (by weight)
PRT Platinum resistance thermometer (typically type Pt 100)
psig pound(s) per square inch (gauge)
psia pound(s) per square inch (absolute)
RH relative humidity
RTU Remote Terminal Unit
scfh standard cubic feet per hour
SD storage device card (memory card for storing datalog files)
temp temperature
USB Universal Serial Bus
V Volts
Warnings
The following general warnings listed below are applicable to this instrument. They are
repeated in the text in the appropriate locations.
!
Where this hazard warning symbol appears in the following
sections, it is used to indicate areas where potentially
hazardous operations need to be carried out.
DANGER
Electric
Shock Risk
Where this symbol appears in the following sections it is
used to indicate areas of potential risk of electric shock.

S8000 User’s Manual
Michell Instruments 1
INTRODUCTION
1 INTRODUCTION
The S8000 is a high precision instrument used for the measurement of dew point in air
and other gases. Relative humidity, moisture content, and other calculated parameters
based on dew point, pressure and temperature of the sample gas can also be displayed.
The S8000 is capable of measuring dew points as low as -60°C (-76°F); it can measure
dew points up to (but not including) the point of condensation (maximum +40°C
(+104 °F)).
Two models of the S8000 instrument are available:
• Low Pressure (1 barg (14.5 psig) max)
• High Pressure (20 barg (290 psig) max)
Figure 1 S8000

S8000 User’s Manual
297488 Issue 4, August 2018
INTRODUCTION
1.1 Operating Principle
The system operates on the chilled mirror principle, whereby a gas sample is passed
into the sensor housing and flows over the surface of the chilled mirror contained
within. At a temperature dependent upon the moisture content in the gas, and the
operating pressure, the moisture in the gas condenses out on the surface of the mirror.
An optical system is used to detect the point at which this occurs, and this information
is used to control the mirror temperature and maintain a constant thickness of the
condensation layer on the mirror surface.
A beam of light from an LED (1) is focused on the mirror surface (2) with a fixed
intensity. As the mirror is cooled, less light is reflected due to the scattering effect of
the condensate formed on the mirror surface. The levels of reflected and scattered light
are measured by two photo-detectors (3 & 4) and compared against a third reference
detector (5) measuring the intensity of light from the LED.
The signals from this optics system are used to precisely control the drive to a solid
state thermoelectric cooler (TEC) (6), which heats or cools the mirror surface. The
mirror surface is then controlled in an equilibrium state whereby evaporation and
condensation are occurring at the same rate. In this condition, the temperature of the
mirror, measured by a platinum resistance thermometer (7), is equal to the dew-point
temperature of the gas.
5
1
3
4
2
7
6
Figure 2 Operating Principle

S8000 User’s Manual
Michell Instruments 3
INSTALLATION
2 INSTALLATION
2.1 Safety
!
It is essential that the installation of the electrical and gas
supplies to this instrument be undertaken by competent
personnel.
2.2 Unpacking the Instrument
23
4
5
1
Figure 3 S8000 Packing
Open the box (5) and unpack carefully as follows (see Figure 3) :
1. Remove the accessories box (4).
2. Lift out the instrument (2) together with its end packing pieces (1) and
(3).
3. Remove the end packing pieces (1) and (3) set the instrument down at
the site of installation.
4. Save all the packing materials for the purpose of returning the instrument
for re-calibration or any warranty claims.

S8000 User’s Manual
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INSTALLATION
The accessories box should contain the following items :
1. Traceable calibration certificate
2. User's manual
3. IEC power cable
4. SD memory storage card
5. Optics cleaning kit
6. Allen Key SMM
7. USB communications cable
8. Pt100 temperature probe (optional)
9. CAT5 ethernet cable (optional)
10. Microscope (optional)
If there are any shortages, please notify Michell Instruments immediately
(see www.michell.com for contact information).

S8000 User’s Manual
Michell Instruments 5
INSTALLATION
2.3 Operating Requirements
2.3.1 Environmental Requirements
The S8000 instrument should either be placed on a firm and level surface in a laboratory
environment, or mounted into a standard 19" rack. Recommended ambient temperature
+20 to +25°C (+68 to +77°F) although the instrument will operate, within specification,
at elevated ambient temperatures of up to +40°C (+104°F), providing the cooling
vents are kept clear and unrestricted. It is essential however that this upper
temperature limit (+40°C (+104°F)) is not exceeded.
A free flow of air around the instrument is required at all times.
The instrument is suitable for mounting in a standard 19" rack.
!
For rack mounted instruments, forced air cooling of the
rack should be considered if operating at high ambient
temperatures.
2.3.2 Electrical Requirements
All versions of the instrument require the following electrical supply:
• 85 to 264 V AC, 47/63 Hz, 100 VA max
• Alarm outputs for all instrument types comprise two sets of changeover
relay contacts, one set for a PROCESS alarm and one set for an
INSTRUMENT FAULT. Both sets of contacts are rated at 24 V, 1 A. NOTE:
THIS RATING MUST NOT BE EXCEEDED.
2.4 Exterior Layout
The controls and indicators relating to the operator interface are located on the front
panel.
The external PRT connection, mains power IEC socket, analog output connector, remote
temperature probe connector, alarm relay connector, the USB socket, and the Ethernet
socket (optional) are located on the rear panel.
Figures 5 and 6 show the layout of these controls for both the rack mount/horizontal
and vertical versions of the instrument. Tables 1 and 2 detail the controls and indicators
and the function key operations.

S8000 User’s Manual
697488 Issue 4, August 2018
INSTALLATION
Front Panel
Figure 4
Front Panel
Item Name Description
1Microscope
Blanking Plug
Used to cover the microscope port when not in use. Also
to be used as a key to remove optics window (see Section
5.3).
2Sensor Housing Exterior housing of the sensor.
See Section 5.3 for information about the sensor head.
3Touch Screen
Display
Displays measured values and enables the user to control
the operation of the instrument.
See Section 3.2 for information about the touch screen and
menu system.
Table 1 Front Panel Controls and Indicators
12
11
13

S8000 User’s Manual
Michell Instruments 7
INSTALLATION
Rear Panel
Figure 5
Rear Panel
Item Name Description
4Gas Input Port
Usually slightly above atmospheric pressure in order to
maintain flow rate over the mirror, but can be up to a
maximum of 20 barg depending upon application.
5Gas Output Port Usually vented to atmosphere.
6Analog Output
Connector
Three, 2-wire output channels, CH1, CH2 and CH3, each
of which may be configured to give either a 0-20 mA or a
4-20 mA current loop output or a 0 to 1 V voltage signal
representing any one of the measured or calculated output
parameters selected.
Spans for each signal output are separately configurable.
Refer to Section 2.5.2.
7
Remote
Temperature
Probe (optional)
6-Pin Lemo socket for connection of remote Pt100
temperature probe.
8Alarms
Process and Fault alarm outputs. Each alarm has one set of
potential free, changeover, relay contacts, common (COM),
normally closed (N/C) and normally open (N/O).
The Process alarm can be configured to operate at a specified
level on any of the measured or calculated parameters.
Refer to Section 2.5.3.
9
USB
Communications
Port
Used for connection to an external computer system for
running application software (optional).
87756
7455711
5910512514513

S8000 User’s Manual
897488 Issue 4, August 2018
INSTALLATION
10
RJ45 Ethernet
Socket
(Optional)
Used for communication with the instrument over a network
connection.
See Section 4.2.3 for details on how to configure the
network settings.
See Section 4 for information on using and installing the
application software.
11
4-wire PRT
bridge output
(Optional)
Banana sockets for external 4-wire measurement of the
internal PRT. Active only when PRT set to External from
Display options, and instrument is in the MEASURE phase.
In this mode the dew-point display is set to read zero, DCC
is set to OFF and manual DCC is also disabled.
12 Flow Control
Valve (Optional)
Used to regulate flow through the sensor when pump is in
use.
13 Pump Input Port
(Optional)
Can be linked to Gas Output port with supplied tubing for
operation with sample pump - NOT TO BE USED ABOVE
ATMOSPHERIC PRESSURE.
14 Pump Output
Port (Optional) Vented to atmosphere when pump is in use.
Table 2 Rear Panel Controls and Indicators
2.5 Rear Panel Connections (All Versions)
!
These tasks should be undertaken only by competent
personnel.
DANGER
Electric
Shock Risk
All the connections to the rear panel are electrical
connections.
Exercise due caution, particularly when connecting to
external alarm circuits which could be at high potential.
Connections to the rear panel of the instrument are explained in the following sections.

S8000 User’s Manual
Michell Instruments 9
INSTALLATION
2.5.1 Power Supply Input
The AC power supply is a push fit into the power input socket as shown in Figure 7 . The
method of connection is as follows:
1. Ensure that both ends of the power cable are potential free i.e. not
connected to an AC power supply.
2. Check that the ON/OFF switch (1) on the power supply connector
is switched to OFF.
3. Push the IEC connector (3) firmly into the power input socket (2).
4. Connect the free end of the power cable to a suitable AC power
supply source (voltage range 85 to 264 V AC, 47/63 Hz) and switch
on the AC supply. The instrument may then be switched on, as
required, using the ON/OFF switch.
Figure 6
Power Supply Input
13
11
2

S8000 User’s Manual
10 97488 Issue 4, August 2018
INSTALLATION
2.5.2 Analog Output Connections
The three analog outputs can be configured to represent any of the directly measured
or calculated output parameters. They are provided as 2-wire signals from a 6-way
connector located on the rear panel of the instrument
.
Each of these outputs can be set up as either a current loop signal (4-20 mA or 0-20
mA) or alternatively, as a 0-1 V voltage signal. The configuration of these outputs, i.e.
parameter represented, output type (current loop or voltage) and upper/lower span
levels are set up via the SETUP Menu Screen (refer to Section 3.2.4).
These signals may be used to control external systems. During a DCC cycle, and for
the HOLD period following a DCC cycle, they are held at the level that they were at
immediately prior to the start of the cycle. When the dew-point measurement is stable,
or if the maximum HOLD period has expired, they are released and will track the
selected parameter throughout the measurement cycle.
The default settings of these analog outputs are:
Channel 1:4-20 mA, dew point, -60 to +20°C
Channel 2: 4-20 mA, ppmV , 0 to 3000
Channel 3: 4-20 mA, flow, 0 to 1000ml
NOTE: The analog outputs are only active during the MEASURE phase. They
will, therefore, be off after switch-on and remain off until the system enters
the MEASURE phase.
The three analog output ports connections are made via a single, 6-way, push fit
connector block as shown in Figure 8 . All outputs are 2-wire signals referenced to a
common 0 V line. To differentiate between the outputs it is recommended that a black
lead be used for each of the COM (common) lines and a separate color for each of the
positive lines.
Figure 7 Analog Output Connectors