MBW 973 Operation And Maintenance Manual

Dew Point Mirror 973

MBW Calibration Ltd.

Seminarstrasse 57

CH-5430 Wettingen / Switzerland

[phone] phone

[phone] fax

0Hwww.mbw.ch

[e-mail]

Operation and

Maintenance Manual

Phone: [phone]
Email: [e-mail]
Web: www.ima.co.uk

UK Distribution by IMA Ltd:
Parkwell House,
Otley Road,
Guiseley, West Yorkshire,
LS20 8BH, England

Warranty

MBW Calibration Ltd. (MBW) warrants the products it manufactures or distributes to be free of
defects in material and workmanship under normal use and service when operated within the
specified design limitations for a period of 12 months from date of initial shipment. Under this
Warranty, MBW will, at its discretion, repair or replace any component that upon examination
by MBW or its duly authorized representatives proves to be defective during the warranty
period provided the system is returned to the factory for inspection and repair shipping
prepaid. Improper or unauthorized maintenance, storage, repair, or alteration of any kind by
personnel other than MBW or its duly authorized representatives may void all warranties.
Warranty may also be voided for misuse, neglect, accident, corrosion, and improper
installation. This Warranty is exclusive and in lieu of any and all other warranties of
merchantability, fitness for a particular purpose, or any other warranty, expressed or implied,
and all other liabilities and obligations on the part of MBW. MBW will not be liable for any
other claims or damages, either direct, indirect, or consequential arising out of the use of its
products.

i

Table of Contents

Table of Contents ..................................................................................................................... i

Welcome................................................................................................................................... 1

How to Use This Manual ......................................................................................................... 1

For More Information ............................................................................................................. 1

OPERATION.........................................................................................................3

Getting Started......................................................................................................................... 3

Turning the 973 On and Off................................................................................................... 3

What You See........................................................................................................................ 3

The Touch Screen.................................................................................................................. 5

The Measuring Head Assembly.............................................................................................9

Dew Point Measurement........................................................................................................ 9

System Configuration ........................................................................................................... 12

Menu Options....................................................................................................................... 12

Display Parameters.............................................................................................................. 13

Graphing Data...................................................................................................................... 13

Control Setup....................................................................................................................... 15

Changing Units..................................................................................................................... 18

Changing Color.................................................................................................................... 19

Analog Outputs .................................................................................................................... 20

Back Panel Connections....................................................................................................... 22

Power Plug........................................................................................................................... 22

Power Switch ....................................................................................................................... 22

RS-232................................................................................................................................. 22

External Temperature.......................................................................................................... 22

Analog Outputs .................................................................................................................... 23

Gas Input and Output........................................................................................................... 23

Barometric Pressure Input................................................................................................... 23

Measurement Tips................................................................................................................. 24

Understand the Measuring Range....................................................................................... 24

Connecting Hoses................................................................................................................ 24

Cooling Requirements ......................................................................................................... 26

INSTALLATION..................................................................................................27

Facility Requirements ........................................................................................................... 27

Environmental...................................................................................................................... 27

Power................................................................................................................................... 27

Preparation for Use ............................................................................................................... 27

Benchtop Use....................................................................................................................... 27

Preparation for Shipping or Transportation ....................................................................... 27

ii

REMOTE COMMUNICATION ............................................................................29

Introduction............................................................................................................................ 29

Hardware Connection & Cabling.......................................................................................... 29

Communications Settings .................................................................................................... 30

Command Syntax .................................................................................................................. 30

General Usage..................................................................................................................... 30

Termination Characters ....................................................................................................... 30

Leading and Trailing Spaces ............................................................................................... 31

Case Sensitivity.................................................................................................................... 31

Numeric Values.................................................................................................................... 31

Command Reference............................................................................................................. 32

Commands Listed By Functional Group.............................................................................. 33

MAINTENANCE .................................................................................................37

Mirror Cleaning...................................................................................................................... 37

Exterior Cleaning................................................................................................................... 38

Front Panel........................................................................................................................... 38

Rear Fan Grills..................................................................................................................... 38

Welcome 1

Welcome

Congratulations! With the 973 Dew Point Mirror you will be able to perform precision dew
point and frost point measurements as well as measurements of other parameters such as
relative humidity. The 973 utilizes a full color active matrix liquid crystal display with an
integral touch panel. It has a high contrast ratio and a wide viewing angle for easy readability.
Data is displayed in large easy to read fonts. Using the on screen buttons and menus, you
can easily configure each line of the display for a variety of humidity, temperature, and
pressure parameters that may be viewed in either SI or non-SI units.

How to Use This Manual

If you have the time and inclination, you can read this manual from front to back. Since we
realize your time is valuable and that you may not wish to do that yet, we recommend the
following approach to familiarize yourself with the 973 and start using it right away.

1. With the 973 at hand, go straight to the

Getting Started section on page 3. From there,

you can qu

ickly learn to use the 973 to make a dew point measurement.

2. Next, read the

System Configuration section beginning on page 12 to learn how to

configure the

system to meet your preferences.

3. Finally, read the

Back Panel Connections section beginning on page 22. That section

identifies all the ele

ctrical and gas connections available on the back panel and explains

how and when to use them.

For More Information

For a more thorough understanding of the 973 and other humidity measurement information,
please read the remaining sections of this manual.

The

Installation section covers bench space, environmental, and p

ower requirements.

The

Remote Communication section discusses the RS-232 interface both from a hardware

and software perspec

tive. It gives details relating to cabling to connect the 973 to a
computer, and gives the syntax and examples of each of the commands that the 973
recognizes.

The

Maintenance section covers topics such as Mirror Cleaning and general maintenance

require

d to keep your 973 performance at its best.

If the information you seek is not in one of the manual’s included sections, never hesitate to
contact us with your questions. Relevant phone, fax, and email contact information is on the
front page of this manual.

Getting Started 3

Operation

Getting Started

This section allows you to set up and start using the 973 right away. You’ll turn the system on
and quickly familiarize yourself with the layout and features of the display and touch screen.
Next, you’ll learn about the optical mirror assembly for later care and cleaning that may be
required. Finally, you’ll use the 973 to measure the dew point temperature. Set your 973 on the
bench and let’s get started!

Turning the 973 On and Off

The 973 needs a source of normal AC power. Have a look at the label on the back panel of the
instrument for the voltage required. Ensure that the required voltage matches that of your
standard laboratory power receptacles.

1. Using the supplied AC power cord, supply the

proper voltage to the instrument by plugging the
cord into the back of the instrument, then into an
AC receptacle of the proper voltage.

2. The power switch is located on the back panel

next to the power cord input. Turn it ON.

The display should become visible within a few
seconds. If nothing seems to happen, check the
power source. There may also be some fuses
located next to the power switch. You can remove
and replace them with known good ones. Suspect
fuses can be tested for continuity with an ohmmeter.

What You See

When power is applied to the 973, the display will activate within a few seconds. A typical
display configuration is depicted below. If you or someone else previously configured your
system, it may look slightly different. But don’t worry, we’ll show you how to set it up the way
you like.

Data
Lines

Fixed
Function
Keys

Menu
Keys

10.00

25.41

-8.41

14.695

Relative Humidity
%

External Temp
°C

Frost Point
°C

At m Pr e ss u r e
psia

Pump

Dew/Frost

Control

Mirror

Check

M irror

Cleaning

4 Getting Started

Data Lines

The first four lines of the display are for numeric or graphic representation of the measured data.
We refer to those first four lines as data lines.

10.00

Relative Humidity
%

If numeric, a data line contains the value to the
left, with the parameter description and units to
the right.

-9.65

Time Span 20.16.30

-10.2

Time Span 00:30:00

-9.8

If graphic, a data line shows a simple graph of
the data over time.

The choice of which parameter is shown on which data line, as well as whether a data line is
viewed as numeric or graphic, is easily selectable. You’ll see how to make these selections
shortly.

Status Bar

Flow Rate

60
30

0

STABLE

Balance
Indicator

+

-

Frost
Density

Hi

0

Mirror
Residue

Hi

0

The status bar contains balance, density,
contamination, and flow rate indicators. The
configuration of the status line is fixed and
never changes.

Fixed Function Keys

Pump

Dew/Frost

Control

Mirror

Check

Mirror

Cleaning

The bottom line of the display contains a row of
fixed function keys. You’ll use these keys to
start and stop the pump, enable and disable
measurement of dew point, and other things.
The function of each of these keys never
changes, and they are always available for
use.

Menu Keys

To the right side of the display is a column of
menu keys. Each of these keys changes
function as needed.

Notice that the bottom key in this column is
different from the rest. The bottom key is used
to cycle the upper keys through the various
menu options. The text on the bottom key
changes to indicate the currently selected
menu option. The text of the upper keys
change based on the functions available in the
menu.

Use this key to change menus

Getting Started 5

The Touch Screen

The 973 utilizes a touch screen for user interaction. To activate a menu option or toggle a
function on or off, simply touch the screen directly over the key or object desired.

Calibrate the Touch Screen

Before using the 973 for the first time, you may need to calibrate the touch screen to your finger
positioning preference. Here’s how –

1. Press and hold the enter key on the numeric
keypad for 3 or 4 seconds. If you’ve done it
correctly, you’ll hear two loud short beeps.
If not, release the key and try again.

2. With the tip of your finger, press the center
of the yellow key in the upper right corner of
the touch screen. It is labeled ‘Touch This
Key’. Once you touch it, the yellow color
goes away and another key turns yellow.

3. Now, touch the yellow key that’s in the lower
left corner of the touch screen. Once you
touch it, the yellow color goes away and you
have successfully calibrated the touch
screen.

4. Test your new touch screen calibration by pressing each of the six blank menu keys on the
right side of the touch screen several times. If they seem not to work well, just repeat the
calibration steps again from the beginning.

You may recalibrate the touch screen as often as needed, however, it is rarely required.

6 Getting Started

Navigating the Menus

The various menus of the right column of keys are navigated by using the key in the lower right
corner of the touch screen. Each time you press the lower right key, a new menu appears on
the keys directly above it. The menu is circular, meaning that once you go past the last menu,
the first one appears again and the process starts over. You can use the +/- key on the keypad
to move backward through the menus. Use the enter key to clear the menu.

Selecting Parameters to Display

Selecting which parameters to display on the data lines is easy. It is done with the Parameter
menu.

1. Use the lower right menu key to select the
Parameter menu. ‘Parameter’ appears on
the key, and the keys above get left pointing
arrows. Notice that each key corresponds
to the data line it points toward.

2. Press the arrow key corresponding to the
data line you wish to change. Notice that
each time you press the arrow key, the
parameter of the data line changes. The
parameter selection is circular, meaning that
once you reach beyond the last available
parameter the first one is again displayed
and the cycle starts over.

3. Change the parameters on any of the other
data lines with the same method.

4. If you like, you may clear the menu keys
when finished by cycling through all the
menus using the lower right key on the
touch screen, or by pressing the enter key
once. Note that this is not required and
nothing is wrong with leaving the Parameter
menu (or any other menu) on the screen.

Getting Started 7

Selecting Graph vs. Numeric Data

Any data line may be viewed either as numeric or as a graph. The Numeric/Graphic menu is
used to toggle any data line between numeric and graph mode.

1. Use the lower right menu key to select the
Numeric/Graphic menu. ‘Numeric/Graphic’
appears on the key, and the keys above
contain left pointing arrows. Notice that
each key corresponds to the data line it
points toward.

2. Press the arrow key corresponding to the
data line you wish to change. Notice that
the data line toggles between numeric or
graph mode each time you press the key.

3. Select numeric or graph mode on any of the
other data lines with the same method.
[

Notice that if a line is currently displaying the Status
Bar, no arrow appears on the adjacent menu key. The
Status Bar is not changeable in the Numeric/Graphic

menu.

]

4. If you like, you may clear the menu keys
when finished by cycling through all the
menus using the lower right key on the
touch screen, or by pressing the enter key
once. Note that this is not required and
nothing is wrong with leaving the
Numeric/Graphic menu (or any other menu)
on the screen.

8 Getting Started

Selecting Units

The data may be viewed in any of the many available units. There are two Units menus used to
change the units of displayed data.

1. Use the lower right menu key to select the
Units menu. ‘Units’ appears on the key, and
the keys above contain current units
indications such as ‘Temp °C’. Notice that
each of the keys contain different types of
units. In this case, the keys do not correspond
to the adjacent data lines, but rather to
different units types.

2. To change temperature units, press the key
labeled ‘Temp’. Notice that the corresponding
units change each time the key is pressed.
Also notice that any data line that is currently
indicating temperature data also changes to
reflect the newly selected units.

3. Change other units (such as pressure, flow
rate, etc.) with the same method.

4. Note that there are two Units menus since
there are so many types of units that may be
changed. The second Units menu is obtained
by pressing the lower right menu key again.

5. If you like, you may clear the Units keys when
finished by cycling through all the menus using
the lower right key on the touch screen, or by
pressing the enter key once. Note that this is
not required and nothing is wrong with leaving
the Units menu (or any other menu) on the
screen.

Getting Started 9

The Measuring Head Assembly

The heart of the 973 Dew Point Mirror instrument is
the measuring head assembly. It is designed to be
highly sensitive and accurate, yet rugged and easily
accessible for periodic mirror cleaning. Although not
required prior to initial operation, you may wish to
familiarize yourself with the location and accessibility
of the mirror and the other optical components within
this assembly.

For further discussion of the measuring head, and
the mirror cleaning procedure, refer to

Mirror

Cleaning on page 37.

Dew Point Measurement

When you power the 973 on, it begins in an idle state. In this state, it measures and displays
temperature, pressure, and flow transducers, but does not yet provide any meaningful humidity
related data. In order to provide humidity data (dew point, frost point, %RH, etc.), the Dew/Frost
Control mode must be enabled and gas must be flowing across the mirror. If %RH is desire d,
note also that an external temperature probe must be connected. For external temperature
probe use, see

External Temperature on page 22.

Starting / Stopping the Pump

Some gas flow is required over the mirror when measuring the dew or frost point temperatur e.
The nominal gas flow desired is approximately 20 to 60 liters/hour (0.2 to 1.0 liters/minute). If
your 973 is equipped with an internal gas pump, you can use it to provide the necessary gas
flow. If not, then you may need to provide for gas flow in some manner.

Use the Pump key on the bottom row of the touch screen to toggle the pump on/off. The Flow
Rate indicator on the status line should indicate that gas is flowing. The actual rate of flow is not
critical, but is best when within the limits previously mentioned. The gas flow may be adjusted
with an external valve, or by changing the pump control parameters. See

Pump Control on

page 17.

Measuring the Room Ambient Dew Point Temperature

Enable Control

Lets use the 973 to measure the dew point temperature of the room by enabling the portion of
the system responsible for cooling and maintaining the mirror at the dew or frost point
temperature. Do so by pressing the Dew/Frost Control key. When enabled, a green bar on
the key illuminates and any dew or frost point temperature indication begins to drop as the
mirror cools toward the dew or frost point temperature. See

Selecting Parameters to Display on

page 6 to select one of those parameters for display.

What You’ll See

When the Dew/Frost Control is enabled, have a look at the Status Bar (if you have your screen
set up to show it). The Status Bar has visual bar graphs that represent Balance, Density, Mirror
Residue, and Flow Rate.

Pump

Dew/Frost

Control

Flow Rate

60
30

0