Thermo Scientific Orion 350 User manual

Thermo Scientific
Orion 320, 350 and 370
PerpHecT®LogR®Meter
User Guide

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This publication supersedes all previous publications on this subject.

Table of Contents
Introduction ............................................1-1
GeneralInformation.......................................1-1
MeterOverview..........................................2-1
MeterDisplay............................................2-1
320MeterKeypad.........................................2-2
350and370MeterKeypad..................................2-3
MeterConnections........................................2-4
LogR Temperature Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Operatingthe320Meter...................................3-1
MeterPowerUp..........................................3-1
SetupMenu .............................................3-1
pHCalibration...........................................3-2
TwoPointAutocalibration.................................3-3
OnePointAutocalibration.................................3-4
ManualCalibration......................................3-5
LogR Temperature Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
LogRCalibration........................................3-7
mV/ORPMeasurements....................................3-8
Automatic Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Manual Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Operatingthe350Meter...................................4-1
MeterPowerUp..........................................4-1
SetupMenu .............................................4-1
pHCalibration...........................................4-3
reePointAutocalibration................................4-4
TwoPointAutocalibration.................................4-5
OnePointAutocalibration.................................4-6
ManualCalibration......................................4-7
LogR Temperature Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
LogRCalibration........................................4-9
mV/ORPMeasurements...................................4-10
RelativemVMeasurements.................................4-10
Automatic Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . 4-10
Manual Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
GLPcheck™ Electrode Diagnostic Procedure . . . . . . . . . . . . . . . . . . . . 4-11
Chapter 1
Chapter 2
Chapter 3
Chapter 4

Operatingthe370Meter...................................5-1
MeterPowerUp..........................................5-1
SetupMenu .............................................5-1
pHCalibration...........................................5-3
reePointAutocalibration................................5-4
TwoPointAutocalibration.................................5-5
OnePointAutocalibration.................................5-6
ManualCalibration......................................5-7
LogR Temperature Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
LogRCalibration........................................5-9
ISE (Concentration) Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
TwoPointISECalibration................................5-11
mV/ORPMeasurements...................................5-12
RelativemVMeasurements.................................5-12
Automatic Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Manual Temperature Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
GLPcheck™ Electrode Diagnostic Procedure . . . . . . . . . . . . . . . . . . . . 5-13
Interfacing the 350 and 370 Meters with
PrintersandComputers ...................................6-1
CustomerServices........................................7-1
Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Meter Self-Test and Checkout Procedures . . . . . . . . . . . . . . . . . . . . . . . 7-1
MeterSelf-Test..........................................7-2
Meter Self-Test Operator Assistance Codes. . . . . . . . . . . . . . . . . . . . . 7-3
320MeterCheck-Out....................................7-3
350MeterCheck-Out....................................7-4
370MeterCheck-Out....................................7-5
OperatorAssistanceCodes ..................................7-6
Assistance ...............................................7-8
Warranty................................................7-8
NoticeofCompliance......................................7-8
CertificateofConformity...................................7-9
Ordering Information and Specifications. . . . . . . . . . . . . . . . . . . . . . 8-1
OrderingInformation......................................8-1
Specifications.............................................8-4
LogR Temperature Accuracy Tables . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Appendix A

Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide 1-1
Chapter 1 Introduction
Thermo Scientific Orion pH and ISE meters are designed for every
application, from basic pH measurements to advanced concentration analysis
using ion selective electrodes. This user guide contains information on the
preparation, operation and maintenance for the 320, 350 and 370 PerpHecT
LogR meters. The 320 meter measures pH, millivolts (mV) and temperature.
The 350 meter measures pH, millivolts (mV), oxidation-reduction potential
(ORP) and temperature. The 370 meter measures pH, concentration (ISE),
millivolts (mV), oxidation-reduction potential (ORP) and temperature.
All PerpHecT meters feature patented digital LogR technology, which allows
fully temperature compensated measurements without a separate ATC probe.
For maximum system accuracy, use Thermo Scientific Orion PerpHecT
and PerpHecT ROSS pH electrodes. PerpHecT meters are microprocessor-
controlled and feature pH autocalibration, patented digital LogR pH
measurement mode, sealed keypads and large easy-to-read LED displays.
PerpHecT meters are ideal for busy, multi-user laboratories or plant
environments. The pH measurements are easy with the help of advanced
features such as autocalibration, LogR mode, automatic temperature
compensation, choice of pH resolution and diagnostic operator assistance
codes.
• The 320 PerpHecT meter is a basic meter designed for routine pH and
mV measurements.
• The 350 PerpHecT meter offers an RS232 interface for connecting the
meter to a printer or a computer. Other features include GLPcheck for
monitoring electrode performance and GLPdoc that creates printouts
that are compatible with good laboratory practice (GLP) requirements.
• The 370 PerpHecT meter offers basic ISE functions for measuring ion
concentrations using an ion selective electrode and an RS232 interface for
connecting the meter to a printer or a computer. Other features include
GLPcheck for monitoring electrode performance and GLPdoc that
creates printouts that are compatible with good laboratory practice (GLP)
requirements.
General Information

1-2 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
Figure 1 – 370 PerpHecT LogR Meter

Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide 2-1
Chapter 2 Meter Overview
A large bright LED display shows results in the main (middle) field.
Temperature is displayed in the upper field. The lower display shows
millivolts. The current operation mode is indicated along the right side of
the display. The buffers used during the last pH calibration are designated by
the indicators along the left side of the display. See Figure 2.
Figure 2 – 370 PerpHecT Meter Display
Meter Display

2-2 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
setup – Indicates that the meter is in the setup menu, which is used to
define or view meter operating parameters.
LogR – Indicates that the meter is in the LogR temperature measurement
or calibration mode. Automatic temperature compensation is activated
in the meter setup menu and achieved through the pH electrode. LogR
function is active when the LogR icon appears in the display.
ATC – Indicates that an ATC probe is connected to the meter and
operational. Manual temperature compensation is activated when the ATC
and LogR symbols are not displayed.
°C – The ATC icon in the upper display is lit when temperature
is measured with an ATC probe. The LogR icon is lit when LogR
temperature measurement is activated. If neither is on, manual temperature
setting is active.
ready – Displayed when the electrode signal has stabilized (pH, conc, rel
mV, mV and °C) and when the calibration standard input has stabilized.
The 320 meter has a six button keypad that is used to control all
meter functions.
Key Function
mode Press to select the measurement mode. Used to initiate LogR
temperature calibration when LogR function is enabled.
yes/res Press to accept settings, calibration points or to change display
resolution.
scroll (▲ ▼)Press to change a setup parameter. Also used in the
measurement mode to scroll manual temperature settings.
cal Press to initiate pH calibration.
setup Press to enter setup menu. Setup menu is entered to change
meter operating parameters and to enter manual calibration
buffer values.
Meter Display Icons
320 Meter Keypad

2-3
Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
The 350 and 370 meters have an eight button keypad used to control all
meter functions.
Key Function
mode Press to select the measurement mode. Used to initiate LogR
temperature calibration when LogR function is enabled.
yes Press to accept settings, calibration points. May also be used to
scroll through the setup menu without changing any parameters.
scroll (▲ ▼)Press to change a setup parameter. Also used in the
measurement mode to scroll manual temperature settings.
print Press to print measurement data.
cal Press to initiate pH, rel mV, or ISE (370 only) calibration.
setup Press to enter setup menu. Setup menu is entered to change
meter operating parameters and to enter manual calibration
buffer values.
res Press to change display resolution.
Figure 3 – PerpHecT Meter Keypad
350 and 370 Meter Keypad

2-4 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
Power Supply – All PerpHecT meters are designed to operate with a 110
V line adaptor, Cat. No. 020125, 220 V line adapter, Cat. No. 020130
or 240 V line adapter, Cat. No. 020135. Plug the line adaptor securely
into the line adapter input on the back of the meter and then plug the line
adapter into an appropriate wall outlet.
Electrode Input – Attach a PerpHecT pH electrode or other pH electrode
with a BNC connector to the BNC input on the back of the meter. Slide
the electrode connector onto the BNC input and then push in and turn the
connector clockwise to lock it into position. Electrodes with U.S. standard
connectors may be used with an adaptor, Cat. No. 090033. Connect
reference electrodes with pin tip connectors by pushing the connector
directly into reference input. See Figure 4.
ATC Probe – Attach an ATC probe to the ATC input on the back of the
meter by sliding the connector straight in until it is firmly in place. Use
only Thermo Scientific Orion ATC probes that are designed for PerpHecT
meters, Cat. No. 927005 (epoxy body), Cat. No. 927006 (glass body) or
Cat. No. 927007 (stainless steel body).
RS232 – Attach the RS232 connector to the RS232 input on the back of the
meter when using a printer or computer (350 and 370 meters only).
Figure 4 – PerpHecT Meter Connections
Meter Connections

2-5
Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
Obtaining accurate pH values depends on both the correct measurement
of standard and sample temperatures and on the compensation for any
variations in these temperatures. This thermal compensation has generally
been accomplished either manually (by measuring sample solution with a
thermometer and then entering the measured temperature on the meter),
or automatically (by placing a separate temperature probe together with a
pH electrode in the solution).
The temperature of a solution affects pH measurements in two ways:
1. The pH of buffers and samples actually changes with temperature. For
buffers, this change is known and is built into the PerpHecT meters.
2. The slope of the calibration, which the meter uses to convert the
raw millivolt readings of the electrode to pH values, changes with
temperature. At 25 °C, a 10 degree change in temperature changes the
slope by 3.4%.
How important is direct temperature compensation to pH measurement?
To see the effects of temperature, look up your approximate sample
temperature on the left side of Table 1. Read across the top to your
approximate pH value. The value shown at the intersection is the error
a 1° C change in temperature will cause in pH measurement without
compensation. Accurate temperature compensation is essential to accurate
pH measurement.
Table 1 – pH Error due to 1° C Temperature Change (in pH units)
Temp.
(° C)
pH 6 or
pH 8
pH 5 or
pH 9
pH 4 or
pH 10
pH 3 or
pH 11
pH 2 or
pH 12
10 0.004 0.007 0.011 0.014 0.018
20 0.003 0.007 0.010 0.014 0.017
30 0.003 0.007 0.010 0.014 0.017
40 0.003 0.006 0.010 0.013 0.016
50 0.003 0.006 0.009 0.012 0.015
60 0.003 0.006 0.009 0.012 0.015
70 0.003 0.006 0.009 0.012 0.015
80 0.003 0.006 0.008 0.011 0.014
90 0.003 0.006 0.008 0.011 0.014
LogR Temperature
Measurements

2-6 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
PerpHecT pH meters allow for direct temperature measurement and
temperature compensation from your pH electrode. With simultaneous
measurement of pH and temperature, the patented digital LogR technology
makes this possible using most standard glass pH electrodes. The system
is based on using the electrical resistance of the glass sensing bulb as the
temperature probe. The logarithm of the resistance of the bulb varies
almost linearly with the reciprocal of the absolute temperature (see
Figure 5). Almost all common pH glasses show a similar decrease in
resistance with increasing temperature, and can be used with other meters.
However, only the exact shape of the curve of PerpHecT electrodes is in
the meter’s memory. To maximize system performance and accuracy, use a
PerpHecT or PerpHecT ROSS pH electrode.
Figure 5 – LogR Resistance vs. Temperature Graph

Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide 3-1
Chapter 3 Operating the 320 Meter
Plug the meter into an approved wall outlet via the power line adaptor. The
entire display (all icons) will be lit for about two seconds. Once all power
up procedures have been completed, the meter automatically advances to the
measurement mode.
Note: The first time the meter is powered up, a meter self-test and check
out should be performed before using the meter for measurements. Refer to
Chapter 7, Meter Self Test for instructions.
Select the setup menu by pressing the setup key until the setup icon on
the display is activated. This menu is used to define, change or view meter
operating parameters. While in the setup menu, the yes key is used to scroll
through the menu without changing parameters and to enter new parameters
into meter memory. If a parameter has been changed, the yes key must be
pressed to activate the change. The scroll (▲ ▼) keys are used to change the
settings within each function. To exit the setup menu, press the mode key.
Slope – The current pH electrode slope in the meter memory will be
displayed. The value is displayed as a percent of theoretical slope. The
default setting is 100%. This function is for display purposes only. The value
cannot be changed in the setup menu. To change the slope value, perform
a two point calibration or set the slope during a one point calibration. Press
the yes key to advance to next menu function.
LogR – When the LogR function is accessed, the LogR icon will be shown
while the upper readout displays the current LogR setting (off for disabled
and on for enabled). Press the yes key to accept the setting. To change
the current setting, press a scroll (▲ ▼) key. Press the yes key to accept.
The measured LogR temperature will be used to calculate temperature-
compensated pH values.
Manual Buffer Option – When the manual buffer option function is
entered, the display will show STD (57d) or SET (5E7). To change the
setting, press a scroll (▲ ▼) key. Press the yes key when the desired setting
is displayed. When the STD option is selected, calibration may only be
performed with standard buffers (pH 4.01, 7.00 and 10.01). When the SET
option is selected, calibration may be performed with user-defined buffers
within the 0 to 14 pH range. If SET is selected, the meter will advance to
setting the manual buffer values. Buffer values must be at least 1 and not
more than 4 pH units apart.
Meter Power Up
Setup Menu
Setup Parameters

3-2 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
A one or two buffer calibration should be performed using fresh buffers
before pH is measured. Always use a fresh aliquot of buffer whenever
calibrating. It is recommended that a two buffer calibration, using buffers
that bracket the expected sample range, be performed at the beginning
of each day to determine the slope of the electrode. This serves the dual
purpose of determining if the electrode is working properly and storing
the slope value in memory. For maximum accuracy, perform a one buffer
calibration every two hours to compensate for electrode drift, using a fresh
aliquot of pH 7 buffer.
When operating in the LogR mode, the meter does not require the use of
a separate ATC probe. The PerpHecT meters measure the resistance of the
pH sensing glass and converts the value to temperature-compensated pH
measurements. For optimum results, PerpHecT electrodes or PerpHecT
ROSS electrodes should be used.
For the best results, it is recommended that the meter be calibrated for
temperature in the LogR mode. Alternately, an ATC probe may be used.
If LogR or an ATC probe is not used, all samples and standards should be
at the same temperature or manual temperature compensation should be
used.
Stir all buffers and samples with a magnetic stirrer while a measurement
is being made. Some magnetic stirrers generate enough heat to change
solution temperature. To avoid this, place a piece of cardboard, foam
rubber, or other insulating material between the stir plate and beaker.
Note: When making measurements in the LogR mode, you must calibrate
for temperature before attempting a pH calibration.
pH Calibration

3-3
Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
1. Attach the pH electrode to the meter.
2. Choose either pH 4.01 and pH 7.00 buffers or pH 7.00 and pH 10.01
buffers; whichever will bracket your expected sample range.
3. Press the cal key to initiate calibration sequence. The display will show
CAL for two seconds. Press the yes key to accept the last calibration
buffer range (7-4 or 7-10) or select one of these calibration ranges using
the scroll (▲ ▼) keys and then press the yes key to accept the buffer
range.
4. The 7 buffer icon will be displayed. Place the electrode in the pH 7.00
buffer. The reading will be displayed and updated as the calibration
continues. When the ready icon is shown, indicating electrode stability,
press the yes key to accept the buffer value.
5. The pH 4 (or pH 10) icon will be displayed. Remove the electrode
from pH 7.00 buffer and rinse it with distilled water. Place the
electrode in either pH 4.01 or 10.01 buffer, depending on calibration
range that was selected. When the ready icon is shown, press the yes
key to accept the buffer value.
6. SLP will be displayed while the calculated slope is displayed.
7. The meter will automatically proceed to the measurement mode. The
ready icon will be shown to indicate electrode stability. The icons
for the type of calibration performed will be shown until another
calibration is performed.
8. If operating in the LogR mode or using an ATC probe, the
temperature-corrected pH reading will be displayed.
9. Rinse the electrode with distilled water and place it into the sample.
Record the pH and temperature directly from the meter display when
the ready icon is displayed or when the electrode signal is stable.
Two Point Autocalibration

3-4 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
1. Attach the pH electrode to the meter.
2. Choose a pH 7.00 buffer. Autocalibration with one buffer can only be
performed using pH buffer 7.00.
3. Press the cal key to initiate calibration sequence. The display will show
CAL for two seconds. Press the scroll (▲ ▼) keys until 7 is displayed
and then press the yes key to accept the calibration range.
4. Place the electrode in pH 7.00 buffer. When the ready icon is shown,
indicating electrode stability, press the yes key.
5. SLP will be displayed while 100.0 (or the previous calibration slope
value) is displayed. This value can be edited using the scroll (▲ ▼)
keys. Press the yes key to save the slope value.
6. The meter will automatically proceed to the measurement mode. The
ready icon will be shown to indicate electrode stability.
7. If operating in the LogR mode or using an ATC probe, the
temperature-corrected pH reading will be displayed.
8. Rinse the electrode with distilled water and place it into the sample.
Record the pH and temperature directly from the meter display when
the ready icon is displayed or when the electrode signal is stable.
One Point Autocalibration

3-5
Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
Note: Manual calibration can be performed with any user-selected
buffer(s). The difference between manual buffer values must be between
one and four pH units.
1. Attach the electrode to the meter.
2. Press the setup key. Press the yes key until STD (57d) or SET (5E7) is
displayed. Select SET and press the yes key. P1 will be displayed. Use
the scroll (▲ ▼) keys to set the user-defined value for the first buffer
and press the yes key to accept the new value. P2 will be displayed.
Use the scroll (▲ ▼) keys to set the user-defined value for the second
buffer and press the yes key to accept the new value. Press the mode
key to return to the measurement mode.
3. Press the cal key. The display will show CAL for two seconds. The last
calibration buffer range will be displayed. Use the scroll (▲ ▼) keys to
select the SET option. Press the yes key to accept the SET option.
4. P1 will be displayed. Place the electrode into the first calibration
buffer. When the ready icon is displayed, the user defined buffer value
will be shown. Press the yes key to accept the value.
5. P2 will be displayed. Place the electrode into the second calibration
buffer. When the ready icon is displayed, the user-defined buffer value
will be shown. Press the yes key to accept the value.
6. SLP will be displayed for two seconds while the calculated slope is
shown.
7. Rinse the electrode with distilled water and place it in the sample.
Record the pH directly from the main meter display and temperature
from upper field when the ready icon is displayed or when the electrode
signal is stable.
Manual Calibration

3-6 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
This procedure should be performed at least once per week to ensure
accurate temperature compensation when operating in the LogR mode.
If the meter is powered down or the electrode is disconnected, the LogR
temperature should be recalibrated. Refer to the Appendix for accuracy
specifications and recommended calibration techniques.
Choose a temperature calibration range that is at least 5° C apart,
depending on your expected operating range. Evenly bracket your expected
sample temperature range. A maximum 20° C range is recommended
for maximum accuracy. For example, for measurements around 20° C,
calibrate at 10° C and 30° C. For temperature span greater than 20°
C, a three-point temperature calibration is recommended. For many
samples, a single-point calibration near the expected sample temperature
will yield adequate results. A constant temperature bath or a hot plate is
recommended to hold the temperature of calibrating solution.
For best results during temperature calibration, it is recommended that a
pH buffer or tap water be used as the temperature calibrating solution. Do
not use distilled water because the conductivity is too low to obtain a good
calibration.
When using the meter for the first time or restarting the meter in the
LogR mode, a LogR temperature calibration must be performed. It
is recommended that at least a two-point temperature calibration be
performed to meet optimum system accuracy. Refer to the Appendix for
additional information.
LogR Temperature
Calibration

3-7
Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
1. To perform a LogR calibration, the LogR function must first be enabled
in setup menu. Press the setup key. Press the yes key until the LogR
icon is shown. Press the scroll (▲ ▼) keys until on is displayed. Press
the yes key to enable the LogR function. Press the mode key to exit the
setup menu. When the LogR function is enabled, the LogR icon will
be shown while the meter is in the measurement mode.
2. In the measurement mode, press the mode key until the meter shows
the LogR icon and CAL on the main display. Press the yes key to begin
the LogR temperature calibration sequence. The last LogR calibration
type (1-PT, 2-PT or 3-PT) will be shown on the display. 2-PT is the
default setting. Use the scroll (▲ ▼) keys to change calibration type
and then press the yes key.
3. The display will show CAL 1 in the main readout. The measured
temperature value, based on the last calibration, will be displayed. Place
the PerpHecT or ROSS PerpHecT pH electrode into a temperature-
controlled pH buffer or tap water solution. Measure the temperature
of the solution using a NIST-traceable thermometer. When the LogR
signal stabilizes, the ready icon will be shown.
4. Adjust the temperature value using the scroll (▲▼) keys. Press the yes
key to accept the value.
5. If a two point calibration was selected, CAL 2 will be displayed on
the main readout. Follow steps 3 and 4 to set the second temperature
value. Repeat the same steps if a three point calibration is selected.
6. The meter will proceed to the pH measurement mode after accepting
the final temperature value.
Note: A calibration may be aborted before saving the final calibration
point by pressing the mode key. This will cause the system to display
ESC, proceed to pH mode and retain to the previous LogR temperature
calibration data.
LogR Calibration

3-8 Thermo Scientific Orion 320, 350 and 370 PerpHecT®LogR®Meter User Guide
1. Press the mode key to select the mV mode. Disable the LogR function
in the setup menu.
2. Connect the ORP electrode to the meter.
3. Place the electrode in a sample. When the reading stabilizes, record the
mV and temperature values.
For automatic temperature compensation, connect an ATC probe to the
meter and disable the LogR function in the setup menu. Attach the ATC
probe to the 3.5 mm phone jack on the rear panel of the meter. See
Figure 4. The 320, 350 and 370 PerpHecT meters can be used with the
PerpHecT epoxy body ATC probe, Cat. No. 927005; the PerpHecT glass
body ATC probe, Cat. No. 927006; and the PerpHecT stainless steel body
ATC probe, Cat. No. 927007.
For manual temperature compensation, disconnect the ATC probe and
disable the LogR function in the setup menu. Manual temperature may
only be set when the LogR function is disabled and there is no ATC probe
connected to the meter. In the measurement mode, use the scroll (▲▼)
keys to manually set the temperature value. This temperature will be used
to calculate temperature-corrected pH values.
mV / ORP
Measurements
Automatic Temperature
Compensation
Manual Temperature
Compensation