Mesalabs 90XL User Manual

90XL™ Meter

User’s Guide

Part No. 901120027 Rev H

© 2018 Mesa Laboratories, Inc. All Rights Reserved

This Page Intentionally Left Blank

Table of Contents

I.

DESCRIPTION ..................................................................................................................4

II.

INDICATIONS FOR USE ...................................................................................................4

III.

SAFETY INFORMATION ...................................................................................................5

IV.

GENERAL OVERVIEW ......................................................................................................6

V.

FEATURES, COMPONENTS, AND CONTROLS ..............................................................7

A. Display Module Holder and IV Pole Holder ..................................................................8

B. Key and Symbol Descriptions ......................................................................................9

C. 90XL Screen Flow Diagram ....................................................................................... 10

D. 90XL Display Screens ................................................................................................ 11

1. MAIN Screen Overview ................................................................................... 11

2. MENU Screen Overview .................................................................................. 12

VI.

OPERATING INSTRUCTIONS ......................................................................................... 13

A. General ...................................................................................................................... 13

B. How to Connect / Disconnect a Sensor Module ......................................................... 14

C. Meter Configuration ................................................................................................... 15

D. Changing the Units of Measure .................................................................................. 16

E. How to Take Measurements ...................................................................................... 18

1. Conductivity and Temperature Measurements ................................................ 18

2. pH Measurements ........................................................................................... 18

3. How to Take Pressure Measurements ............................................................. 19

F. How to Verify Sensor Module Calibrations .................................................................. 21

1. 90XL Conductivity/Temperature Sensor Module ............................................. 21

2. 90XL pH Sensor Module .................................................................................. 23

3. 90XL Pressure Calibration Verification ............................................................ 24

G. Timer Function ........................................................................................................... 25

VII.

CALIBRATION INSTRUCTIONS ..................................................................................... 26

A. General Information ................................................................................................... 26

B. Resetting Factory Defaults (Applies to all module types) ........................................... 26

C. How to calibrate the conductivity/temperature sensor module ................................... 27

1. Low Range Conductivity Calibration ................................................................ 28

2. Mid-Range (Standard) Conductivity Calibration ............................................... 29

3. High-Range Conductivity Calibration ............................................................... 31

D. How to Calibrate the pH Sensor Module .................................................................... 33

E. How to Calibrate the Pressure Sensor Module .......................................................... 35

VIII.

CLEANING, DISINFECTION, AND STORAGE ............................................................... 36

IX.

BATTERY INFORMATION .............................................................................................. 37

X.

90XL ACCESSORIES ...................................................................................................... 38

XI.

TROUBLESHOOTING ..................................................................................................... 40

XII.

USER ASSISTANCE AND FACTORY SERVICE ............................................................ 41

XIII.

90XL SPECIFICATIONS .................................................................................................. 42

XIV.

LIMITED WARRANTY ..................................................................................................... 43

I.

DESCRIPTION

The 90XL meter is designed to be used by hemodialysis professionals to measure and display
readings of conductivity, temperature, pH, and pressure of the dialysate fluids used in
hemodialysis delivery systems.

The display module includes the LCD display as well as the user interface. It is used in
conjunction with specific measurement sensor modules that contain the appropriate sensor for
the desired measurement. The following sensor modules are currently available:

• Conductivity / temperature

• pH

• Pressure (Gauge or differential)

The multichannel LCD screen allows the display of up to 4 simultaneous readings from any
combination of sensor modules.

The 90XL timer function allows routine event timing.

NOTE: Throughout this User’s Guide, the terms 90XL Instrumentation system and 90XL meter
are equivalent descriptors for this device.

II.

INDICATIONS FOR USE

The 90XL instrumentation system is intended for use by hemodialysis professionals to measure
the conductivity, temperature, pH, and pressure of the dialysate solution associated with
hemodialysis delivery systems. Water purification specialists may also use the 90XL meter to
verify proper characteristics of the water used in hemodialysis. These parameters are key
indicators of system performance that require periodic monitoring and adjusting to maintain safe
and effective hemodialysis systems.

4

III.

SAFETY INFORMATION

WARNINGS AND CAUTIONS

WARNING:

without first verifying accuracy of measurement functions. Using the device without verifying
accurate function could result in improper calibration of the dialysis delivery system. An
improperly calibrated dialysis delivery system could result in compromised dialysis treatment(s)
and/or patient injury.

Mesa Labs recommends verifying sensor module calibration using National Institute of
Standards and Technology (N.I.S.T.) traceable reference standards before use or whenever
inaccurate readings are suspected.

WARNING:

device cannot be used inside an oxygen tent.

CAUTION:

sensor module is temperature-compensated for NaCl solution. Other solutions, such as
potassium chloride (KCl), may result in an inaccurate calibration.

CAUTION:

system’s primary sensors, controls, and/or monitors.

CAUTION:

ends in liquids, as this may result in damage to the instrument and/or the sensor modules.

CAUTION:

the display module or sensor modules, as this will cause damage.

CAUTION:

serviceable parts inside and it will void the warranty.

CAUTION:

CAUTION:

It should not be disposed of in a landfill.

WARNING:

Polyester, Aluminum, Acrylic, Glass, Natural Polypropylene, *NorylTM, Stainless Steel, Santoprene,
Silicone, ABS Plastic, Polycarbonate Plastic, Powder Coat Paint. No latex or latex containing
materials are used in the manufacture of the device.

*NorylTM is a registered trademark of SABIC Innovative Plastics IP B.V.

The 90XL Display Module and its attached sensor modules should never be used

The device is not suitable for use in a potentially explosive environment. The

Use only sodium chloride (NaCl) standard solution. The conductivity/temperature

DO NOT use the 90XL Instrumentation System in place of the dialysis delivery

DO NOT submerse your 90XL display module or the sensor module connector

DO NOT use abrasive cleaning agents and/or full-strength bleach or acid to clean

DO NOT open the display module or sensor modules. There are no user-

Federal (USA) law restricts this device to sale to or by order of a physician.

Dispose of this device properly.

The user can be exposed to the following materials when using this device:

5

IV.

(Condo/temp, Pressure)

measurement

conductivity measurement

The 90XL meter is a portable, multifunction meter designed to measure the conductivity, pH,
temperature, and pressure of the dialysate fluids associated with hemodialysis delivery systems,
and of the water used in hemodialysis.

The display module houses the electronic circuitry, navigation keys, digital display, and
rechargeable lithium-ion battery. The four navigation keys are labeled by the display according to
context.

The individual sensor modules contain the appropriate sensors and circuitry for measuring the
desired parameter of the dialysate solution or hemodialysis water. The sensor modules attach to
the display module with cables that plug into connectors on the meter. Up to four different sensor
modules may be simultaneously connected to the display module for the desired measurements.

Measurements for conductivity and temperature are taken as the solution flows through the
dialysate lines to which a sensor module is connected. pH measurements may be taken by
using the pH sensor module directly from a container using the dip configuration. For water
purity measurements, a water sample is removed from the water purification system via a valve
and then tested using an appropriate sampling method. The 90XL pressure sensor module can
be used to verify the accuracy of arterial and venous monitors, measure negative pressure and
differential pressure of the delivery system fluid.

GENERAL OVERVIEW

In-Line method using adapters

6

Dip sample method for pH

Sample tray and syringe for

Navigation Keys

Display

Conductivity/Temp Sensor Module

pH Sensor Module

and probe

Pressure Sensor Module

Connections

V.

FEATURES, COMPONENTS, AND CONTROLS

Sensor module measurements are shown on the display module screen. Using the navigation
keys, the user may access numerous display screens and views to select individual functions,
such as:

Adjust date and time

Adjust screen contrast and brightness

Select units of measure for readings

Obtain detailed information about a
sensor module

Sensor Module

Calibrate sensor modules

Restore factory default values

Time events

Access help screens

Select auto-off time

LCD

7

A. Display Module Holder and IV Pole Holder

The Display Module is supplied with a protective holder. The holder may be used as a tilt stand
on a flat surface, it may be used with the supplied IV Pole Holder to mount the Display Module
on an IV pole, or the Display Module may be inserted with the LCD and buttons facing inside to
protect it during transport and storage.

Case holder for the Display Module Case holder used as a tilt stand on a flat

surface

Place the Display Module in the case/holder The IV Pole Holder conveniently slips into
with the screen side down as a protector slots in the back of the case/holder

8

B. Key and Symbol Descriptions

SCROLL UP A LIST OF

SELECTIONS, SCROLL UP

ONE LINE IN HELP

SCROLL DOWN A LIST OF

SELECTIONS, SCROLL

DOWN ONE LINE IN HELP

SCROLL DOWN AN ENTIRE

PAGE IN HELP

SELECT THE CHANNEL OF

INTEREST ON THE MAIN

SCREEN

RETURN TO THE MAIN

SCREEN

START THE TIMER

FUNCTION

STOP THE TIMER

FUNCTION

CHANGE THE POSITION OF

THE READINGS IN DUAL

CHANNEL DISPLAY

RETURN TO THE

PREVIOUS SCREEN

PRESS TO MANUALLY

TURN OFF THE SYSTEM

PRESS TO DISCONITUE OR

ACESS THE SYSTEM MENU

RESET THE TIMER

FUNCTION TO ZERO

SAVE A SELECTED

PARAMETER

SELECT A MENU ITEM

RESTART A CALIBRATION

SETTING UNTIL THE UNIT

ADVANCE TO THE NEXT

PROCEDURE

PRESS TO SAVE A

IS TURNED OFF

CALIBRATION STEP

9

C. 90XL Screen Flow Diagram

10

Channel Select Icon

Units of

M

easure

the display module)

Battery Charge Indicator

CH$ (Not in Use)

Key Labels

Condo + Temp

D. 90XL Display Screens

1. MAIN Screen Overview

Dual Channel

Channel number (matches the
number connector at the top of

The 90XL screen that displays all real-time measurement information is called the MAIN screen.
The MAIN screen can display up to 4 channels of information based on the number and types of
sensor modules that are connected. The readings from all sensor modules are displayed
simultaneously on the one MAIN screen. If you are viewing multiple channels, there may be a
need to select a particular channel for further actions. This may be done by pressing the key
labeled . This will scroll the selection indicator ( ) down one channel for every press of the

key. The scrolling sequence is “CH 1 through CH 4, then back to CH 1…, etc.” Unused channels
on the display are ignored during the scrolling function.

The SWAP function on the MAIN screen is used to swap the dominant and subordinate readings
within a conductivity and temperature channel. Simply select the channel you would like to
change using the key, and press SWAP. (See Figure 1 below)

Fig. 1

The SWAP key has no affect for a single parameter channel.

11

2. MENU Screen Overview

The MENU key on the MAIN screen will advance you to the list of channel specific, as well as
system related functions.

NOTE: The selected channel on the MAIN screen continues to be displayed on the MENU
screen. Return immediately to the MAIN screen by pressing the MAIN key.

Scroll with the up/down arrows to highlight a menu item, then select using the “SEL” key.

12

VI.

OPERATING INSTRUCTIONS

A. General

(a) Turn the 90XL ON…

To turn on the instrument, press the left most key at the bottom of the display. It is marked
with the symbol.

(b) Connect sensor module(s) to the 90XL meter

Select the sensor module or sensor modules that you would like to use and connect
them to the ports at the top of the instrument. The system will sense the type of sensor
module or sensor modules that are connected, and automatically orient the channels on
the display.

(c) Take measurements…

Once the sensor module(s) are connected to 90XL meter, you are ready to take your
measurements.

WARNING:

Institute of Standards and Technology (N.I.S.T.) traceable reference standards before
taking measurements, or whenever inaccurate readings are suspected.

(d) Turn the 90XL OFF…

The 90XL may be turned off manually by pressing the OFF key at the bottom of the MAIN
screen. Additionally, if an AUTO-OFF (see configuration section) function has been
enabled, the instrument will power down automatically if no key activity is sensed during
the selected time period.

Mesa Labs recommends verifying sensor module calibration using National

13

B. How to Connect / Disconnect a Sensor Module

To connect a sensor module to the 90XL display module:

1. Turn the display module ON by using the left-most key, labeled with the symbol

2. The sensor module may be connected to any vacant port.

3. Plug the connector into the port until a slight click is felt.

There is a slight pause while the sensor module establishes communication with the
display module. The 90XL will then display the reading on the channel that matches the
sensor module connector.

To disconnect a sensor module from the 90XL Display Module:

Using your fingers, gently pull straight away from the socket to remove the connector
from the port. Do not turn or rotate the cable end. Cover the port with the protective cap
to prevent dirt, dust or fluids from entering the connector.

14

MENU Screen

CONFIGURATION Screen

“CONFIGURATION”

C. Meter Configuration

Detailed information

about the selected

sensor module

Select

Using the arrow keys, move cursor to

select digits and set the date. Press

SAVE to advance to the time screen

Choose the time interval for

the auto-off feature. Time

selected is the time after

last key action.

(See note below)

NOTE: For Auto-off,

contrast, and brightness

settings; press the

TEMP key to save the

setting for the current

session only. Press the

SAVE key to keep the

setting as a default.

Using the arrow keys, move cursor

to select digits and set the time.

Press SAVE to advance to return

to the main configuration screen

Scroll to a Menu

item and press

select

Use the arrow keys

to adjust display

brightness

(See Note at left)

Use the arrow
keys to adjust

display contrast

(See Note at left)

15

D. Changing the Units of Measure

Units of measure may be changed for conductivity, temperature, and pressure by using
the following procedures. Once new units of measure have been selected, they will be
retained in the sensor module until changed again by the user.

Conductivity units:

Select the channel displaying
conductivity on the MAIN screen using
the arrow keys.

Make sure that conductivity is the
dominant parameter being displayed
and press MENU. Use the SWAP key to
change the dominant parameter if
necessary.

Select “UNITS OF MEASURE” from the
MENU screen.

Scroll to the units desired using the
arrow keys and press “SEL”. After a brief
pause, the display will return to the
MAIN screen and display the parameter
in the new units.

Temperature units:

Select the channel displaying
temperature on the MAIN screen using
the arrow keys.

Make sure that temperature is the
dominant parameter being displayed (if
not press SWAP) and press MENU.

Select “UNITS OF MEASURE” from the
MENU screen.

Scroll to the units desired using the
arrow keys and press “SEL”. After a brief
pause, the display will return to the
MAIN screen and display the parameter
in the new units.

16

Pressure units:

Select the channel displaying pressure
on the MAIN screen using the arrow
keys.

Select “UNITS OF MEASURE” from the
MENU screen.

Scroll to the units desired using the
arrow keys and press “SEL”. After a
brief pause, the display will return to the
MAIN screen and display the parameter
in the new units.

NOTE: pH units are standard and can not be changed.

17

E. How to Take Measurements

1. Conductivity and Temperature Measurements

A.

Turn the display module ON by using the left-most key, labeled with the

symbol.

B.

Connect a conductivity/temp sensor module to any available port on the
display module.

C.

Choose one of the following measurement methods:

Sample Kit –
Mesa P/N 503110017

Syringe Sample tray

Sample Method: Insert the sensor

end of the conductivity/
temperature sensor module
into the container of test
solution as shown above. Draw
sample solution steadily
through the sensor module.
Note the display output while
the solution is flowing. When
the display is stable, take your

In-line Method: Connect condo/temp

sensor module directly to the
delivery system using the
Hansen connectors as shown
above. Reestablish flow
through the sensor module
and take your readings when
the display is stable.

reading.

2. pH Measurements

Module cable connected to 90XL display module

Sample Method: Insert the pH sensor module electrode into the sample as shown

above. When the display is stable, take your reading.

Hansen Fittings

18

3. How to Take Pressure Measurements

Turn on the 90XL meter and attach a pressure sensor module to any open port on
the top of the display module. Once the pressure sensor module is sensed,
pressure will be displayed in the appropriate channel section of the LCD screen.

The 90XL pressure sensor module can be used to verify the accuracy of arterial
and venous monitors, measure negative pressure and differential pressure of the
delivery system fluid.

WARNING

Use of transducer protectors is required when measuring pressure in liquid lines to
prevent intrusion of fluids into the pressure sensor module.

CAUTION:

If a transducer protector becomes wetted, it will not transmit pressure accurately
and must be replaced with a dry protector.

Module cable connected to 90XL display module

Disposable transducer protectors

Mesa P/N 503110023

19

IMPORTANT:



To 90XL Display Module

Open

Transducer Protector

Adapter

Before measuring pressure, first verify that the display reads “0” with both
pressure ports open to atmospheric pressure. If necessary, zero the pressure
function using the procedure in the calibration section of this user’s guide.

Positive or Negative Pressure

To measure either positive or negative pressure, attach monitor line tubing to the
“Gauge” port. The “Ref” port must be open to atmosphere.

to positive or negative Negative Pressure Measurement
pressure source

Differential Pressure Measurement

To measure differential pressure, attach
monitor tubing to the “Gauge” and “Ref”
Luer ports on the pressure sensor
module. Pressure will read positive only
if the greater of the two measurement
points is connected to the “Gauge” port.

In-line and negative pressure adapters,
as well as monitor lines are available as
90XL accessories.

Artificial Kidney

Dialysis Machine

Negative Pressure

20

F. How to Verify Sensor Module Calibrations

Verify that the measurement sensor module is properly calibrated before use or whenever
inaccurate readings are suspected. When required, always use reference standards that
are traceable to the National Institute of Standards and Technology (N.I.S.T.) and that
have not expired or are past the open bottle time.

1. 90XL Conductivity/Temperature Sensor Module

a) 90XL Conductivity

CAUTION:

conductivity/temperature sensor module is temperature-compensated for NaCl
solution. Other solutions, such as potassium chloride (KCl), may result in
inaccurate calibration.

Gather the following supplies:

· 14.0 mS conductivity standard solution (NaCl) Mesa P/N 02.0027

· 90XL Sample Kit Mesa P/N 503110017

To verify calibration of the conductivity/temperature sensor module:

Use only sodium chloride (NaCl) standard solution. The

1.

2.

3.

4.

5.

14.0 mS conductivity
standard solution

Center sensor holder

To rinse the sample tray and sensor module, pour approximately 50 ml of
fresh reference solution into the sample tray. Insert the conductivity sensor
module into the center sensor holder of the tray.
Insert the syringe assembly to the top male Hansen fitting of the sensor
module. Draw rinse solution through the sensor module, and expel through
the sensor module.
Discard the rinse solution – do not pour used solution back into the original
container.
Pour approximately 50 ml of fresh solution into the rinsed sample tray. Make
sure the conductivity sensor module is inserted into the center sensor
holder.
Draw standard solution slowly through the sensor module and observe the
reading on the display. If the value on the display reads within specified
limits based on the standard solution value used, then calibration is not
needed. If this displayed value falls outside of specified limits, then
calibration is required. See the section entitled “Calibration and
Maintenance”.

21

b) 90XL Temperature Verification

Flow

Dialysis

Delivery

Machine



 

The 90XL temperature calibration may be verified against any N.I.S.T. traceable
standard, or a second 90XL sensor module. Liquid must be moving through the
sensor module when a temperature reading is taken.

To verify temperature calibration of the conductivity/temperature sensor
module:

1. Place the 90XL condo/temp sensor module in a liquid flow path in series
with the standard to be used. (See figure below)

NOTE: If the temperature standard to be used is a dip type probe or a glass

thermometer, a holder must be used to allow flow around the sensing
element and the correct immersion level must be observed.

2. After approximately one minute of flow through the sensor module, observe
the temperature reading on the display module.

NOTE: If the temperature of the liquid in the flow path is different from the

surrounding (ambient) temperature, the temperature of the liquid will be
closer to the ambient temperature at the downstream temperature
measuring point than at the upstream measuring point. The magnitude of
the difference can be measured by reversing the direction of flow through
the two sensors.

IMPORTANT NOTE: The temperature function of this sensor module cannot be
calibrated by the user. Our experience indicates that if erroneous or inaccurate
temperature readings are noted, it is almost always due to a faulty sensor module.
Call Mesa Labs for assistance.

NIST Traceable
Temp Standard

90XL

22

2. 90XL pH Sensor Module

Gather the following supplies:

· 7.00 pH buffer solution, Mesa P/N 02.0031

· 90XL Sample Kit, Mesa P/N 503110017

To verify calibration of the pH sensor module:

1.

2.

3.

4.

5.

pH buffer solution To 90XL pH Sensor Module

Rinse the sample tray and the pH sensor probe with some of the buffer
solution to eliminate any contaminants. Discard the rinse solution – do not
pour used solution back into the original container.
Pour approximately 50 ml of fresh solution into sample tray.
Insert the pH probe into the outer sensor holder. Gently swirl the solution in
the tray and allow the display reading to stabilize.
Observe the reading on the display. If this displayed value is within
specification based on the value of the buffer solution used, then calibration
is not needed. If this value is outside of specifications, then calibration is
needed. See the section entitled “Calibration and Maintenance”.
Using appropriate pH buffer solutions, calibration may be verified at values
other than pH 7.00. Note that pH 10.00 buffer is temperature sensitive and
may not display 10.00, except at 25.0°C. See label for temperature
compensation information.

23

3. 90XL Pressure Calibration Verification

Positive or negative gauge pressure may be checked against a mercury
manometer or other N.I.S.T. traceable standard.

To verify calibration of the pressure sensor module:

1.

2.

3.

NOTE: If the display does not read zero, refer to the “Calibration and Maintenance”

4.

5.

The 90XL “Ref” port must be open to the atmosphere.

Connect the 90XL pressure sensor module to the display module.

With the “Gauge” port open to atmospheric pressure, the display should
read “0 mmHg”.

section of this User’s Guide.

Connect the 90XL and the reference standard using the stop cock and
monitoring lines as shown below. Check for leaks.

Apply positive or negative pressure to both the 90XL pressure sensor
module and the reference standard to verify accuracy.

NIST

Traceable

Pressure

Standard or

Mercury

Manometer

24

G. Timer Function

Event Timing

To access the timer function:

1.

2.

3.

4.

Select MENU from the MAIN screen and scroll to TIMER using the arrow
keys.

Press START to begin event timing; Press STOP to stop event timing.

Press RESET to return the timer to zero. You may start to time another
event at this point.

Press MAIN to return to the MAIN screen. This also resets the timer to zero.

25

VII.

CALIBRATION INSTRUCTIONS

A. General Information

SENSOR MODULE CALIBRATION -The 90XL display module does not require
calibration, although the menu options on the display module are used to calibrate the
connected measurement sensor modules. Mesa recommends that users verify sensor
modules values against non-expired NIST-traceable solutions before use and calibrate
(adjust) the meter only when these verifications are out of tolerance.

NOTE: Yearly factory calibrations are recommended on the Conductivity/Temperature
and Pressure sensor modules. Factory Calibrations stickers are located on the sensor
module and contain last known calibration date and calibration due date.

CAUTION:

of Standards and Technology (N.I.S.T.). Mesa Laboratories reference solutions are highly
recommended and are the same solutions used in the manufacture and factory
calibration of your instrument. DO NOT use expired or out of date Solutions.

CAUTION:

conductivity/ temperature sensor module is temperature-compensated for NaCl solution.
Other solutions, such as potassium chloride (KCl), may result in inaccurate calibration.

NOTE: Select the sensor module that you plan to calibrate by scrolling to it on the MAIN
screen. When CALIBRATION is selected from the MENU screen, all procedural and on­line help information will be related only to the type of sensor module that was selected.

Always use reference standards that are traceable to the National Institute

Use only sodium chloride (NaCl) conductivity standard solution. The

26

B. Resetting Factory Defaults (Applies to all module types)

This procedure may be selected from the calibration menu and, when performed, will
set the selected sensor module back to its original factory calibration state.

If this option is selected, the screen at the right will appear for the user to confirm that this
is the procedure desired (YES) or return to the MAIN screen (MAIN or NO) to begin
again.

WARNING:

procedure and prior to taking any measurements.

Always verify calibration sensor module calibration after performing this

C. How to calibrate the conductivity/temperature sensor module

There can be up to 3 (three) calibration procedures for conductivity:

1.

2.

3.

The 90XL conductivity/temperature sensor module is capable of measuring
conductivities through a range of 1 uS to 200 mS. For the typical range of final
dialysate conductivities, the sensor module needs to be calibrated at the mid­range only. This will yield high accuracy and precision in this range, with
reasonable accuracy and precision at the low and high extremes. If a higher level
of accuracy and precision is needed at the extreme ends of the total range, then
the sensor module should be calibrated using the optional “air-zero” (Low-range)
and 100.0 mS (High-range) calibration procedures. If enhanced accuracy and
precision are required throughout the entire conductivity range, then all three
calibration procedures should be performed in the order as indicated above: (i.e.,
Low--> Mid -->High)

To enter the calibration mode for the selected sensor module:

First, select the appropriate condo/temp module on the MAIN screen by using the

From the MAIN screen press MENU. Scroll down using the down arrow key
to “CALIBRATION” then press “SEL”.

Low range (Air-zero) – no standard solution required
Mid-range (Standard) – 13.40 or 14.00 mS standard solution required
High range – 100.0 mS standard solution required

key.

27

1.

Low Range Conductivity Calibration

PROCEDURE DISPLAY

· No reference solution is required.

· Make sure a condo/temp sensor module is attached.

After “CALIBRATION” has been entered, Select “AIR
ZERO” from the next menu list.

Step 1 – Draw DI or RO water through
the sensor module to rinse. Empty the sensor module
as completely as possible and allow to dry.
Press NEXT to continue…

NOTE: Gently tap the cell to expel droplets, or let dry.
This initial step may be performed in advance of the
actual calibration procedure.

Step 2 – The 90XL will read the cell (theoretically
zero) and perform an evaluation based on the factory
set value. Press NEXT to continue...

Step 3 – If the evaluation is successful, the calibration
information will be stored within the sensor module.

Step 3 – If the displayed factory cal value is greater
than 0.02 mS, the AIR ZERO calibration will fail
indicating possible sensor module malfunction. Press
ABORT to exit. If the calibration fails on multiple
attempts, call Mesa Labs for assistance.

28

2.

Mid-Range (Standard) Conductivity Calibration

PROCEDURE DISPLAY

· 14.0 or 13.4 mS Reference Solution

· 90XL Sample Kit

· Make sure a condo/temp sensor module is attached.

After “CALIBRATION” has been entered,
Select either 14.00 or 13.4 mS STANDARD from the
next menu list. (14.00 mS is chosen for this example.)

Step 1 - Empty any liquids from the sensor module.
The value of conductivity read internally by the 90XL
must be less than 1 mS to proceed. The factory
calibration value is displayed in this step also.

Step 2 - Rinse the sensor module by drawing
reference solution up through it. The value read
internally must be within 0.2 mS of the reference value
to proceed to the next step. If the factory value is off
by more than 0.2 mS, calibration will not be
performed. Press ABORT and contact Mesa Labs.

Step 3 - Empty reference solution from the sensor
module, and discard. The 90XL must detect a value of
less than 1 mS to proceed.

Step 4 - Draw fresh reference solution slowly through
the sensor module. While reference solution is
flowing, the 90XL must detect 4 stable conductivity
values within 0.2 mS of the reference to proceed to
the next step.

NOTE: Draw slowly so that up to 10 seconds of flow
can be maintained.

29

Step 5 - Expel the reference solution from the sensor
module and discard. The 90XL must detect an internal
value of less than 1 mS to proceed.

Step 6 - Draw fresh reference solution through the
sensor module for verification. While reference
solution is flowing, the 90XL must detect 4 stable
conductivity values for verification before proceeding.

Final Step - Calibration is complete. Calibration
information is stored within the sensor module.

OR OR

If during Step 6, the calibration value
differs from the verification value by more than

0.02 mS, the calibration will fail. Press ABORT to exit.
If the calibration fails on multiple attempts, call Mesa
Labs for assistance.

30

100.0

mS

HIGH

STEP

1

100 mS

CAL

V

alue must

be less

than 4 mS

STEP

2

100 mS

CAL

DRAW

REF. SOLUTION

V

of

the reference

to

proceed.

STEP

4

100 mS

CAL

SLOWLY

DRAW

REF. SOL

to proceed.

3.

High-Range Conductivity Calibration

PROCEDURE DISPLAY

· 100.0 mS Reference Solution

· 90XL Sample Kit

· Make sure a condo/temp sensor module is attached.

After “CALIBRATION” has been entered,
Select 100.0 mS HIGH from the next menu list.

Step 1 - Empty any liquids from the sensor module.
The value of conductivity read internally by the 90XL
must be less than 4 mS to proceed. The factory
calibration value is displayed in this step also.

Step 2 - Rinse the sensor module by drawing
reference solution up through it. The value read
internally must be within 4 mS of the reference value
to proceed to the next step.

Step 3 - Empty reference solution and discard. The
90XL must detect a value of less than 4 mS to
proceed.

Step 4 - Draw fresh reference solution slowly

through the sensor module. While reference solution
is flowing, the 90XL must detect 4 stable conductivity
values within 4 mS of the reference to proceed to the
next step.

14.00 mS STANDARD

13.40 mS STANDARD

AIR ZERO

SET FACTORY DEFAULTS

CALIBRATION HELP

EMPTY CELL

to proceed



FACTORY mS VALUE

“XX.XX” mS

THROUGH THE CELL

alue must be within 4 mS

STEP 3
EMPTY CELL
DISCARD RINSE

Value must be less than 4 mS
to proceed.

THROUGH THE CELL
4 stable values within 4 mS
of the reference are required

100 mS CAL

31

Step 5 - Expel the reference solution from the sensor

STEP

6

100 mS

CAL

SLOWLY

DRAW

REF. SOL.

to proceed.

FINAL

STEP

100 mS

CAL

CALIBRATION

COMPLETE

INFORMATION…

100 mS

CAL

module and discard. The 90XL must detect an internal
value of less than 4 mS to proceed.

STEP 5
EMPTY CELL
DISCARD REF. SOL.
Value must be less than 4 mS
to proceed.

100 mS CAL

Step 6 - Draw fresh reference solution through
the sensor module for verification. While reference
solution is flowing, the 90XL must detect 4 stable
conductivity values for verification before proceeding.

Final Step - Calibration is complete. Calibration
information is written to the sensor module.

OR OR

If during Step 6, the calibration value
differs from the verification value by more than

0.25 mS, the calibration will fail. Press ABORT to exit.
If the calibration fails on multiple attempts, call Mesa
Labs for assistance.

FOR VERIFICATION
4 stable values are required

SENDING CALIBRATION

CALIBRATION FAILED
CAL VALUE DIFFERS BY
MORE THAN 0.25 mS FROM
VERIFICATION VALUE.

Press ABORT to exit

32

STEP

1 pH

7.00 CAL

PLACE

pH

PROBE

IN

STEP

2

pH 7.00 CAL

REMOVE

pH

PROBE

D. How to Calibrate the pH Sensor Module

GENERAL INFORMATION

The pH calibration procedure is identical for each of the pH buffer standards. Described
below is the procedure for the 7.00 pH standard, since this is the one commonly used. If
you desire to calibrate the sensor module with 4.00 buffer solution, a 7.00 pH calibration
should always be done first, then 4.00 may be performed.

PROCEDURE DISPLAY

· 7.00 or 4.00 pH buffer Solution

· Sample Kit or clean beaker

· Make sure a pH sensor module is attached.

First, select the pH sensor module on the MAIN
screen using the key. Press MENU and select

“CALIBRATION”. Select “7.00 pH” from the next
screen.

NOTE: If 4.00 pH is selected, the following screen will
appear: Press NEXT to continue.

NOTE:
ALWAYS CALIBRATE
WITH pH 7.00 FIRST

Press ABORT if pH 7.00 has
not been done or press NEXT
to continue.

Step 1 - Remove pH buffer solution bottle from
sensor. Place about 50 ml of buffer solution in the
sample tray or beaker and place the pH sensor
module in the outer sensor holder and allow to

RINSE BUFFER

Press NEXT to continue.

stabilize. Press NEXT to continue.

Step 2 - Remove the pH sensor from the sample tray
and discard the rinse buffer solution. Press NEXT to
continue.

DISCARD RINSE BUFFER

Press NEXT to continue.

7.00 pH

4.00 pH

SET FACTORY DEFAULTS

CALIBRATION HELP

 FACTORY pH VALUE

x.xx pH

33

Step 3 - Pour about 50 ml of fresh buffer solution into
the sample tray. Place the pH sensor in the outer
sensor holder and allow reading to stabilize. The
displayed factory pH value should be within 0.2 pH
unit of the reference solution value. Press NEXT to
continue.

Step 4 - When the pH reading stabilizes on the
display, press the SAVE button. Slow stabilization
times may indicate a need to replace the pH
electrode. As in the previous step, the displayed
factory pH value must be within 0.2 pH unit of the
reference used.

OR

pH sensor module calibration has failed. Call Mesa
Labs for assistance.

OR

Final Step - Store your pH sensor module with the
soaker bottle attached filled with enough soaker
solution or 4.0 pH buffer solution to cover the glass
bulb.

NOTE: If the Factory pH value is “out of range”, the
pH sensor may have exceeded normal life (12-18

FINAL STEP
CALIBRATION FAILED

Factory value and reference
differ by more than 0.2 pH.
Sensor may
need replacing. Press
Abort to continue.

months with proper care) and may need to be
replaced. Call Mesa Labs for assistance.

To replace the pH probe, grasp the black base of the
probe and gently twist it counterclockwise to unlock it,
then pull it straight out. Plug the new
one in. After it is seated, twist gently clockwise to lock
it in. Do not allow fluids to enter the sensor module
connection while the probe is not installed. Calibrate
the new probe according to the procedure starting on
the previous page.

34

E. How to Calibrate the Pressure Sensor Module

PROCEDURE DISPLAY

Make sure the pressure sensor module is connected
to the display module. Remove all monitor lines and
transducer protectors from both “Gauge” and “Ref”
sensor module ports. Both ports on the sensor
module must be open to atmosphere.

Select the pressure module on the MAIN screen using
the key.

PRESS “MENU” from the MAIN screen and scroll to
“CALIBRATION” using the arrow keys. Press “SEL” .

At the next screen, scroll to “PRESSURE ZERO” and
press “SEL”

Step 1 - Assure that both pressure ports are open
to atmosphere at the sensor module. When the
pressure is stable on the display, press “SAVE”.

Final Step - Calibration is complete.
Calibration information is stored within the sensor

FINAL STEP
CALIBRATION COMPLETE

SENDING CALIBRATION
INFORMATION…

module.

OR OR

If the factory value differs from zero by more than 10
mmHg, the pressure zero calibration will fail. Press
ABORT to exit. If the calibration fails on multiple
attempts, call Mesa Labs for assistance.

CALIBRATION FAILED

Factory Value was not within
10 mmHg of zero

Press ABORT to exit.

PRESSURE ZERO

SET FACTORY DEFAULTS

CALIBRATION HELP

STEP 1 mmHg ZERO CAL
WHEN PRESSURE IS STABLE
PRESS SAVE

Factory Value must be
within 10 mmHg of zero.



FACTORY mmHg VALUE

X.XX

mmHg ZERO CAL

35

VIII.

CLEANING, DISINFECTION, AND STORAGE

CAUTION:

DO NOT leave any disinfectant solution in sensor modules, longer than 10 Minutes.

Display Module and Sensor Modules

If necessary, wipe the exterior of the display module with a soft cloth dampened with a mild soap
solution. If disinfection is required, use household bleach (5.25%) at a dilution of 1 part bleach to
99 parts water.

The 90XL display module and sensor modules should be stored in a clean, dry environment
between 0°C and 50°C. It may be stored connected to the AC charger when not in use.

CAUTION:

damage the front panel overlay as well as the case.

CAUTION:

electronics.

DO NOT use abrasive materials or organic solvents such as acetone. They may

DO NOT allow liquid to enter the display module which may damage the

Conductivity/Temperature Sensor Module

Rinse the sensor thoroughly with RO/DI water after use.

CAUTION:

is required, use household bleach solution as describes above. The condo/temp sensor module
should be rinsed with RO/DI water and allowed to air dry. This will prevent deposits from forming
on the electrodes which could affect accuracy.

DO NOT allow fluids to enter the sensor module electrical connector. If disinfection

pH Sensor Module

Rinse the sensor module thoroughly with RO/DI water after use. If disinfection is required, use
household bleach solution as describes above. Store your pH probe in the soaker bottle and
filled with enough soaker solution or 4.0 pH buffer solution to cover the glass bulb at the end of
the probe.

CAUTION:

DO NOT allow fluids to enter the sensor module electrical connectors.

Pressure Sensor Module

Wipe the exterior of the sensor module with a soft cloth dampened with mild soap solution. If
disinfection is required, use household bleach solution as describes above.

CAUTION:

DO NOT allow fluids to enter the sensor module connector.

CAUTION:

The pressure sensor module should be stored with transducer protectors on the Luer ports, and
carefully protected from impact or moisture damage.

DO NOT allow fluid to enter the pressure port connectors.

Sample Kit

Rinse sample tray and syringe with RO/DI water and store in a clean, dry place.

36

IX.

WARNING - Use only the charger supplied by Mesa Laboratories. Use of any other charger will
void the warranty, could cause damage the instrument, or cause personal injury.

CAUTION:

inside. Return the Display Module to Mesa Labs or authorized distributor for service.

CAUTION:

CAUTION:

The lithium-ion rechargeable battery in the 90XL meter is designed to provide years of reliable
service. After 500 complete charge/discharge cycles, it will retain approximately 80% of its
original capacity. The amount of time that a fully charged battery will operate the 90XL meter
depends greatly on how brightly the display’s backlight is illuminated. At full brightness, the
running time will be less than half the running time when the backlight is turned off.

Sensor modules use significantly less power than the display module and won’t affect the
amount of operating time as much as the backlight.

BATTERY INFORMATION

Do not open or dismantle the 90XL meter as there are no user serviceable parts

Do not charge the 90XL when ambient temperature is greater than 45°C. (113 °F)

If the battery fully discharges, the date and time functions must be reset.

90XL Battery Facts

• From a fully discharged state, the display module battery may take up to 4.5 hours to fully
charge.

• The 90XL meter may be operated continuously while charging.

• The 90XL meter may be left connected to the charger continuously.

• The 90XL meter may be stored approximately 1000 hours while turned off before a fully
charged battery is depleted.

• The sensor modules do not contain a power source; they receive their power from the
display module.

• State of battery charge will not affect accuracy of measurements. When the battery falls
below a certain level, the meter will turn itself off.

BATTERY INDICATOR

- FULLY CHARGED

- 50% CHARGED

- BATTERY LOW

(less than 1 Hr of

power remaining)

37

X.

90XL ACCESSORIES

The following accessories are available for the 90XL meter.

Item

Charger 201110021

Replacement pH electrode 201110005

90XL User’s Guide 901120027

Standard Solutions Visit dialyguard.mesalabs.com

pH buffer Solutions Visit dialyguard.mesalabs.com

Sampling Kit

P/N 503110017

Negative Pressure Adapter

P/N 350120002

38

Part No.

Transducer Protector

Monitoring Line and Stopcock

P/N 503110023

P/N 350120005

In-Line Adapter
P/N 350120003

Carrying Case w/ Cut Outs

P/N 201110003-1

IV Pole Connector

P/N 503110024

Display Module Cover/Holder

P/N 303110075

pH Probe Assembly

P/N 201110005

Sensor Module Extension Cable

2 Meter P/N 350110015
5 Meter P/N 350110016

39

XI.

1.

2.

3.

4.

5.

TROUBLESHOOTING

Do not open the display module or the sensor modules. There are no user-serviceable
parts inside, and it will void the warranty.

If the display module does not turn on, or shuts down right after it turns on, the battery
may be depleted. Charge the display.

If the display module becomes unresponsive and the charger is connected, press all four
buttons at the same time to reboot it. If the display module is still unresponsive, contact
Mesa Labs or an authorized distributor for service.

If a sensor module does not show a reading after connection to the display module (a
slight pause is normal) the sensor module may be inoperable. Contact manufacturer or
an authorized distributor for service.

If the pH sensor module can not be calibrated, or stabilization time becomes
unacceptably slow, the pH probe may have reached the end of its life expectancy and
may need to be replaced. See page 33 for instructions, and contact manufacturer or an
authorized distributor for service.

40

XII.

USER ASSISTANCE AND FACTORY SERVICE

Mesa Laboratories, Inc. (Mesa Labs) provides user assistance, full repair and calibration /factory
certification services for the 90XL Meter and its components at its corporate headquarters or at
authorized distributor locations throughout the world.

NOTE: Yearly factory calibrations are recommended on the Conductivity/Temperature and
Pressure sensor modules. Factory Calibrations stickers are located on the sensor module and
contain last known calibration date and calibration due date.

Warranty Information - DO NOT attempt to repair or modify the meter, as this will void the
warranty. For warranty information contact Mesa Labs or your local distributor. Any service
required other than cleaning or calibration must be referred to either Mesa Labs or an authorized
distributor.

How to Reach Us

Please contact Mesa Labs for further information and product return instructions.

Write to: Mesa Laboratories, Inc.
12100 W. 6th Avenue
Lakewood, Colorado 80228 USA

Telephone: [phone], USA or Canada
(+) 1-303-987-8000

Fax: (+) 1-303-987-8989

E-mail:

On the web: dialyguard.mesalabs.com

Service – [e-mail]

41

XIII.

90XL SPECIFICATIONS

TECHNICAL pH Conductivity Temperature Pressure

Range

Resolution

Accuracy

Temperature
Compensation

0 to 14 pH

0.01 pH

+/- 0.1 pH

units

units

units

0 to 200.0 mS 10 to 90˚C -600 to +1600 mmHg

0.1 µS from 0 - 80 µS

0.001 from 0 to 22.00 mS

0.01 from 22.00 to 80.00 mS

0.1 above 80.00 mS

±0.35% of reading + 0.002mS

from 0 to 1.99 mS

± 0.20% of reading + 0.002

from 2 to 29.99 mS

± 0.50% of reading above

30 mS

10 to 90˚C (optimized for 20

to 40˚C)

±0.1˚ from 10

to 40˚C

+/- 0.1°C

±1.0 mmHg from 0 to 199

± 1.5 mmHg from 200 to 300

± 0.5% of reading + 1 mmHg
above 300 mmHg and below

0.1 mmHg

mmHg gauge

mmHg gauge

0 mmHg

PHYSICAL

3.3” x 6” x 1.5” 9.9 ounces Battery 3.6 V Lithium Ion, rechargeable

Dimensions Weight Power Battery Type

ENVIRONMENTAL

Temperature Relative Humidity

CONDITIONS

Storage 0°C to 50°C

(-32°F to +122°F)

Operating 10°C to 35°C

(50°F to 95°F)

0 to 90% RH
(Non-Condensing)

0 to 80% RH
(Non-Condensing)

42

XIV.

LIMITED WARRANTY

MESA LABORATORIES, INC. warrants to the original purchaser of the 90XL Meter that it will
repair or replace, at its option, any malfunctioning or defective part without charge for the terms
listed below. Parts used for replacement are warranted for the remainder of the original warranty
period. Mesa Laboratories, Inc. will provide labor without charge to the original purchaser for a
warranty repair.

WARRANTED COMPONENT WARRANTY TERM *

90XL Display Module 12 Months

TO OBTAIN WARRANTY SERVICE, the original purchaser must deliver, at its own expense, the
product to MESA LABS at the address below:

Mesa Laboratories, Inc.

12100 W. 6th Avenue

Lakewood, Colorado, USA 80228

*Please complete and include the Service Order Form from our website.

OPENING THE DISPLAY MODULE OR SENSOR MODULE WILL VOID THE WARRANTY

THIS WARRANTY DOES NOT COVER:

1)

Disposable items such as the battery or pH probe.

2)

Routine calibration or cell cleaning.

3)

Defects caused by:

a)

modification, alteration, repair or service of the product by anyone other than
MESA LABS or an authorized service center

b)

misuse due to negligence or accident

c)

operation or maintenance of the product in a manner contrary to the
manufacturer’s instructions

Any express warranty not provided herein, and any remedy for breach of contract that but for this
provision might arise by implication or operation of law, is hereby excluded and disclaimed. The
implied warranties of merchantability and of fitness for any particular purpose are expressly
limited to the terms mentioned above. Some states do not allow limitations on the duration of an
implied warranty, so the above limitation may not apply to you.

Under no circumstances shall MESA LABS be liable to the original purchaser or to any other
person for any special or consequential damages, whether arising out of breach of warranty,
breach of contract, or otherwise. Some states do not allow the exclusion or limitation of special
or consequential damages, so the above exclusion or limitation may not apply to you.
This warranty gives you specific legal rights, and you may also have other rights that vary from
state to state. For further warranty information, contact Mesa Laboratories, Inc.

43