MBA Instruments MLA 900 User manual

Operating Instructions
Operation
Maintenance
Approvals
MLA 900
Conductivity meter
for light petroleum products
Title

Operating Instructions 8011381 V2.0 © MBA Instruments GmbH
2
Document information
Document ID
Title: Operating Instructions MLA 900
Order No.: 8011381
Version: 2.0
Status: 2010-06
Subject
Product name: MLA 900
Software: Version 1.1
Manufacturer
MBA Instruments GmbH
Friedrich-List-Str. 7 · D-25451 Quickborn · Germany
Phone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Trademarks
IBM is a trademark of the International Business Machine
Corporation.
MS-DOS and Windows are trademarks of the Microsoft
Corporation.
Other product names used in this document may also be
trademarks and are only used for identification purpose.
©MBA Instruments GmbH. All rights reserved.
Warning symbols
Warning levels / signal words
GEFAHR
Immediate hazard which will result in serious injury or death.
WARNUNG
Risk or hazardous situation which could result in serious injury or
death.
VORSICHT
Hazard or unsafe practice which may result in minor or moderate
personal injury.
NOTICE
Hazard or unsafe practice which could result in property
damage.
Information symbols
Hazard (general)
Hazard in explosion-hazardous locations
Hazard by explosive substances/mixtures
Important technical information for this product
Nice to know
Supplementary information
Link to information at another place

Contents
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 3
1For your own safety … . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 General safety in hazardous locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Essential safety notes for the MLA 900 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2Notes on application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Approved use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.1 Designated use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.2 Application restrictions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.3 Regulations and standards fulfilled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Official approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.1 Definitions of terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2.2 Approval for the MLA 900 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3Preparing for operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 Supply schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
4.1 Display unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.1 Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.2 Switching on and off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.3 Measuring value displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 Fault/limit value displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3 Performance test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.4 Measuring procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.5 Measures in the event of a fault/damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.1 Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.1.1 Cleaning the probe cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.1.2 Cleaning the measuring probe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.1.3 Cleaning the display unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.2 Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.3 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
6Storage, transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.1 Correct storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.2 Short-distance transports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.3 Correct shipping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.4 Shipping for repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7Approval certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Contents

Contents
4 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH

For your own safety …
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 5
MLA 900
1For your own safety …
General safety
Essential safety notes

6 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
For your own safety …
1.1 General safety in hazardous locations
1.2 Essential safety notes for the MLA 900
b Observe the following safety notes when assembling and operating the instrument,
during maintenance and repair, and when exchanging parts – for your own protection.
The most important safety rules are:
WARNUNG:
b Before using the instrument for the first time in a hazardous location:
Observe all the safety instructions in these operating instructions.
VORSICHT: Risk of wrong measurements
b Before using the MLA 900: carry out a performance test ( → S. 21, §4.3) –
always to be done outside of the hazardous locations.
WARNUNG: Hazard when potential equalisation is missing:
b Before the measuring probe is lowered into the liquid container: Safely
connect the ground clamp of the display unit with the liquid container
(potential equalisation).
WARNUNG: Hazard when enclosure is open
b Never open the instrument enclosure as long as it is in a hazardous
location.
WARNUNG: Hazard by unsafe instrument
b If there is any reason to assume that the instrument is no longer safe: shut
down the instrument and protected it against unauthorised use.

Notes on application
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 7
MLA 900
2Notes on application
Designated use
Application restrictions
Official approval

8 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Notes on application
2.1 Approved use
2.1.1 Designated use
Measuring function
The MLA 900 determines the electrical conductivity and the temperature of petroleum
products such as occur, for example, in aviation fuels and in other petroleum products.
During the filling process, pumping or filtering, these liquids may become electrostatically
charged. If, in addition, there is an inflammable gas mixture present in the ambient
atmosphere, there is a danger that the gas mixture will be ignited by a discharge spark,
which means that it may explode. To evaluate this risk, the electrical conductivity of the
liquid is measured (see German standard DIN 51 412-T02-79, »Determining electrical
conductivity, field procedure«).
The conductivity is stated in the physical unit »pS/m« (picosiemens per meter). This unit
corresponds to »c.u.« (conductivity unit), which is still commonly used in the petroleum
industry:
Ambient conditions
The MLA 900 is designed as a measuring instrument for outside use.
b Use the MLA 900 at an ambient temperature of –20 °C … +60 °C (–4 … +140 °F).
Outside this temperature range it can no longer be guaranteed that the instrument will
function correctly.
2.1.2 Application restrictions
The MLA 900 may only be used to measure the conductivity and temperature of petroleum
products, such as petrol, kerosene and oils/greases. Other liquids such as acids or
solvents containing chlorinated hydrocarbons, for example, can damage the measuring
probe.
●At temperatures above +60 °C (140 °F) there is a danger that caustic liquid
from the battery may escape and damage the electronics. Apart from this,
the LC displays may be damaged (irreversible blackening).
●At temperatures of below –20 °C (–4 °F), the LC displays in the display unit
may freeze, resulting in the LC display enclosure bursting.
●Low temperatures affect the flexibility of the probe cable.
b Avoid bending the probe cables in low temperatures.
Otherwise the probe cable could brake due to the sheath becoming brittle.
component clean with avoid contact with
measuring probe
probe cables
petrol
spirit (ethanol)
isopropanol
acids
chlorinated hydrocarbons (CHC)
methanol
acetone
1pS
m
1c.u.=

Notes on application
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 9
2.1.3 Regulations and standards fulfilled
The MLA 900 measuring procedure corresponds to:
●German standard DIN 51 412-T02-79 (»Determining electrical conductivity, field
procedure«)
●ASTM 02624 »Standard Test Methods for Electrical Conductivity of Aviation and
Distaillate Fuels«
The technical design of the MLA 900 corresponds to:
●European standard EN 60079-0:2006
●European standard EN 60079-11:2007
●European standard EN 60079-26:2007
●European Council Directrive 94/9/EC (ATEX guideline)
●German »Ordinance on electrical appliances in hazardous locations« (»Verordnung
über elektrische Anlagen in explosionsgefährdeten Räumen«, ElexV) of 13 December
1996.
2.2 Official approval
2.2.1 Definitions of terms
●An explosive mixture is a mixture of gases, vapours, mists or dusts in which a reaction
continues independently after ignition.
●An explosive atmosphere contains explosive mixtures of gases, vapours, mists or dusts
with air, including usual admixtures (for example, humidity) under atmospheric
conditions. Atmospheric conditions are here defined as total pressures of 0.8 to 1.1 bar
and gas mixture temperatures of from –20 °C to +60 °C.
A dangerous explosive atmosphere occurs when in the event of an ignition injury may
be caused to persons as a direct or indirect result of the explosion.
●Hazardous locations are those areas in which a dangerous explosive atmosphere may
occur due to local and operational conditions.
Hazardous locations are divided into zones on the basis the probability (in terms of time
and place) of the presence of dangerous explosive atmospheres:
– Zone 0 includes areas in which a dangerous explosive atmosphere is present
»constantly or for longer periods«; for example, in tank facilities.
– Zone 1 covers areas in which a dangerous explosive atmosphere »occasionally«
occurs; for example, in the vicinity of refuelling nozzles.

10 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Notes on application
2.2.2 Approval for the MLA 900
Approved area of application
The MLA 900 is approved for use in hazardous locations in which inflammable gases,
vapours or mists may occur (EEx ia IIB T6). The MLA 900 measuring probe is approved for
use in Zone 0, the display unit for use in Zone 1.
Prescribed operating conditions
The following applies for the use of the MLA 900 conductivity meter in the area of
application as defined in the »Ordinance on electrical appliances in hazardous locations
(ElexV)«:
WARNUNG: Hazards in explosions-hazardous locations
●The MLA 900 is intended exclusively for mobile use at different locations.
●The measuring probe of the MLA 900 is approved for use in containers for
inflammable liquids (Hazardous Location Zone 0).
●The display unit of the MLA 900 may only be used in Hazardous Location
Zone 1.
●The measuring probe may only be used in such liquids against which the
materials of which it is made offer adequate chemical resistance (
→ S. 8,
§2.1.2).
●Damaged measuring probes may not be used in Zone 0.
●Before the measuring probe is taken to Zone 0, all plug and threaded cable
connections must be checked.
●The measuring probe may only be used with the appropriate display unit.
●Before the measuring probe is lowered into the liquid container (tank), the
ground clamp of the display unit must be connected to the container to
equalize the electric potentials.
Approval document → S. 36

Preparing for operation
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 11
MLA 900
3Preparing for operation
Supplied parts
Assembly

12 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Preparing for operation
3.1 Supply schedule
When delivered, the MLA 900 consists of:
●display unit with ground clamp
●measuring probe
●probe cable, 2 m long
●probe cable, 10 m long
●transport case
Bild 1 MLA 900 supply schedule
VORSICHT: Risk of damage
●Tight bending may damage the cable (cable breaks).
●Damaged cables must not be used in hazardous locations.
b Never buckle the probe cable and do not bend the cables too far.
b At temperatures below 0 °C (32 °F), treat the probe cable with particular
care – because the cable sheath may become brittle at these temperatures.
Avoid tight bending (risk of breakage).
●Keep the transport box even if you do not wish to use it when operating the
MLA 900. It may be useful as a shipping packaging.
●List of spare parts → S. 30, §5.3
Nr.: 930XXX
PTB02ATEX2201X
display unit measuring
probe
probe cable
2m
probe cable
10 m
ground clamp

Preparing for operation
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 13
3.2 Assembly
The MLA 900 consists of four instrument components (measuring probe, display unit,
ground clamp, probe cables). – Note: These components will only conform to the technical
safety regulations for the petroleum industry when used as an assembled unit.
Measuring probe and display unit are a matching pair
Display unit and measuring probe have been individually adapted in the factory. If a
different probe is connected, the measuring accuracy cannot be guaranteed.
b Only connect a measuring probe to a display unit with the identical serial number on it.
Probe cables
b Connect the display unit to the measuring probe with one of the probe cables supplied.
(Choose the cable length which is the best for the application.)
Ground clamp
b Make sure that the ground clamp is firmly attached to the display unit (threaded
connections, cable lugs).
b Do not start up the MLA 900 if this is not sure.
Bild 2 Connecting the probe cable
You can also connect the probe cables to each other to have a 12 m length of
cable. Greater cable lengths can be obtained by using further cable sections
(order designations
→ S. 30, §5.3).
The maximum allowable total cable length is 24 m.
WARNUNG: Risk by wrong equipment
b Use only use cables of the type supplied to connect the display unit and the
measuring probe.
It is not permitted to operate the instrument with other cables in hazardous
locations.
Nr.: 930XXX
PTB02ATEX2201X

14 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Preparing for operation

Handling
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 15
MLA 900
4Handling
Instrument display
Performance test
Measuring procedure

16 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Handling
Bild 3 Display unit
Conductivity
Temperature
Please close cover after use!
Function test: Press the serial number
of the probe to to red button
display: 1000 cu + 10 cu
CAUTION: Do NOT change battery
within the explosive areas!
Nach Gebrauch Deckel schlieen!
Funktionstest: Seriennummer der Sonde
an roten Testpunkt halten
Anzeige: 1000 cu + 10 cu
ACHTUNG: Batteriewechsel darf NICHT
im EX-Bereich vorgenommen werden!
temperature
measured
light
sensor
ON
OFF
conductivity
measured

Handling
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 17
4.1 Display unit
4.1.1 Handling
Handling during transport
b Always use the carrying handle to carry the instrument.
⊗Do not use the cover flap or the cable brackets to carry the instrument.
Handling during measurement
b During measurements, hold the display unit safely in your hand.
4.1.2 Switching on and off
b Switching on: Open the cover flap of the display unit.
➝The MLA 900 automatically starts up when the light sensor is exposed to light.
b Switching off: Close the cover flap.
➝When the flap is closed, the MLA 900 automatically shuts off.
4.1.3 Measuring value displays
b Watch out for fault and limit value indications ( → S. 19, §4.2).
If you put the display unit down while measuring: make sure that it is standing
securely – because it might be pulled down by the weight of the measuring
probe, or even fall into the liquid container.
WARNUNG: Risks by wrong use
b In hazardous locations the display unit may only be operated within
»Zone 1«.
b Before the measuring probe is introduced into the liquid container (tank):
connect the ground clamp of the display unit to the container.
left-hand display: right-hand display:
temperature of the measuring probe/
the liquid conductivity measured
Display range:
-199 °C … + 199 °C Measuring range: 0 … 1999 pS/m
The MLA 900 is approved for measurement in hazardous locations only in a
temperature range of
–20 °C … + 60 °C. This is the temperature range where
the MLA 900 fulfils the stated specifications.

18 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Handling
Bild 4 Fault/limit value displays
Conductivity
Temperature
Please close cover after use!
Function test: Press the serial number
of the probe to to red button
display: 1000 cu + 10 cu
CAUTION: Do NOT change battery
within the explosive areas!
Nach Gebrauch Deckel schlieen!
Funktionstest: Seriennummer der Sonde
an roten Testpunkt halten
Anzeige: 1000 cu + 10 cu
ACHTUNG: Batteriewechsel darf NICHT
im EX-Bereich vorgenommen werden!
BAT BAT
conductivity measured
is lower than 50 pS/m
– or –
fault
battery
is almost spent
measuring range
overflow
(conductivity measured
is greater than 1999 pS/m

Handling
MLA 900 Operating Instructions V 2.0 8011381 © MBA Instruments GmbH 19
4.2 Fault/limit value displays
BAT (shown on both displays)
Meaning Measures/instructions
The life of the built-in battery is almost over.
The battery voltage is lower than 8 V
(new battery: 9 V).
b Replace the battery ( → S. 29, §5.2).
▲~
Meaning Measures/instructions
The measuring probe is outside the liquid.
b Immerse the measuring probe in the
liquid.
The conductivity of the sample solution is
lower than
50 pS/m.
b Observe the safety rules and carry out
the measures laid down for this case.
▲~ 1 xxx + constantly changing temperature measuring valuet
Meaning Measures/instructions
The probe cable is broken.
b Carry out a performance test ( → S. 21,
§4.3).
b If unsuccessful: change the probe
cable. Then carry out another
performance test.
Measuring probe is badly contaminated or
moist (splashed with water).
b Clean and dry the measuring probe
(
→ S. 27, §5.1).
WARNUNG: Risk by damaged cable
b Do not operate the instrument in hazardous locations if the probe cable is
damaged or defective.
b Only change the probe cable outside hazardous locations.
1
Meaning Measures/instructions
Measuring value is greater than
1999 pS/m.
b Check whether the conductivity of the
liquid can actually be greater than
1999 pS/m.
Measuring probe is badly contaminated or
moist (splashed with water).
b Clean and dry the measuring probe
(
→ S. 27, §5.1).
MLA 900 is damaged.
b Carry out a performance test ( → S. 21,
§4.3).

20 MLA 900 Operating Instructions V2.0 8011381 © MBA Instruments GmbH
Handling
Bild 5 Performance test
MLA 900
Conductivity
Temperature
Please close cover after use!
Function test: Press the serial number
of the probe to to red button
display: 1000 cu + 10 cu
CAUTION: Do NOT change battery
within the explosive areas!
Nach Gebrauch Deckel schlieen!
Funktionstest: Seriennummer der Sonde
an roten Testpunkt halten
Anzeige: 1000 cu + 10 cu
ACHTUNG: Batteriewechsel darf NICHT
im EX-Bereich vorgenommen werden!
min.
max.
Nr.: 930XXX
PTB02ATEX2201X