RKI Instruments SC-01 User manual

SC-01
Operator’s Manual
Part Number: 71-0136RK
Revision: P2
Released: 12/28/06
www.rkiinstruments.com

2 • Warranty SC-01 Operator’s Manual
Warranty RKI Instruments, Inc., warrants the SC-01 Single Gas Monitor sold by us to
be free from defects in materials, workmanship, and performance for a
period of one(1) year from the date of shipment from RKI Instruments, Inc.
This includes the instrument and the original sensor. Replacement parts
are warranted for one (1) year from the date of their shipment from RKI
Instruments, Inc. Any parts found defective within their warranty period will
be repaired or replaced, at our option, free of charge. This warranty does
not apply to those items, which by their nature, are subject to deterioration
or consumption in normal service, and which must be cleaned, repaired, or
replaced on a routine basis. Examples of such items are as follows:
Warranty is voided by abuse including mechanical damage, alteration,
rough handling, or repair procedures not in accordance with the instruction
manual. This warranty indicates the full extent of our liability, and we are
not responsible for removal or replacement costs, local repair costs,
transportation costs, or contingent expenses incurred without our prior
approval.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES
AND REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER OBLIGATIONS
OR LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC., INCLUDING BUT NOT
LIMITED TO THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. INNO EVENT SHALL RKI INSTRUMENTS, INC., BE LIABLE
FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL LOSS OR DAMAGE OF ANY KIND
CONNECTED WITH THE USE OF ITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO
FUNCTION OR OPERATE PROPERLY.
This warranty covers instruments and parts sold to users only by
authorized distributors, dealers, and representatives as appointed by RKI
Instruments, Inc.
We do not assume indemnification for any accident or damage caused by
the operation of this gas monitor and our warranty is limited to replacement
of parts or our complete goods.
Absorbent cartridges
Filter elements, disks, or sheets
Pump diaphragms and valves

SC-01 Operator’s Manual Table of Contents • 3
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Protective Rubber Boot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Alligator & Belt Clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Sensor Retainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
LCD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Printed Circuit Boards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Alarm LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Buzzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Vibrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Start Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Start-up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Performing a Fresh Air Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Turning Off the SC-01. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Operation in Measuring Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Using the SC-01 With the Optional Extender Cable . . . . . . . . . . . . . . . . . . . . . . 21
Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Setup Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Using Setup Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Setting the Date and Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Performing a Fresh Air Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Performing a Span Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Updating the Alarm Point Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Updating the Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Entering Measuring Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4 • Table of Contents SC-01 Operator’s Manual
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Replacing the Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Replacing the Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Changing the SC-01s Target Gas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
WARNING: Understand this manual before operating the 01 Series.
Substitution of components may impair intrinsic safety.
To prevent ignition of a hazardous atmosphere, batteries
must only be changed in an area known to be
nonhazardous. This unit has not been tested in an
oxygen enriched atmosphere (above 21%).

SC-01 Operator’s Manual Introduction • 5
Introduction
Using an advanced microprocessor controlled detection system, the SC-01
Personal Single Gas Monitor detects the presence of one of a variety of
toxic gasses depending on the sensor installed. The SC-01 has the ability
to recognize which sensor is installed so that changing the target gas is as
easy as changing the sensor to a different type calibrated sensor. The
SC-01’s compact size and easy-to-use design makes it ideally suited for a
wide range of applications, including sewage treatment plants, hazardous
waste sites, petrochemical facilities, oil fields, chemical plants, and
semiconductor plants. The SC-01 offers the following features:
• Sensor recognition for plug & play capability
• Available extender cable for remote sensor capability
• Compact design
• Fast, accurate response with digital liquid crystal display (LCD)
• Visual, audible, and vibration alarms
• Microprocessor control for reliability, ease of use, and advanced
capabilities
• Peak, STEL, and TWA indication
• Over range alarm
• Gas, battery, sensor failure, and system failure alarms
• Over 250 hours operation on one set of alkaline batteries
• CSA classified intrinsically safe for Class I, Division I, Groups A, B, C,
and D hazardous atmospheres (PENDING)
WARNING: The SC-01 detects toxic gases which can be dangerous
or life threatening. When using the SC-01, you must
follow the instructions and warnings in this manual to
assure proper and safe operation of the unit and to
minimize the risk of personal injury.

6 • Specifications SC-01 Operator’s Manual
Specifications
Table 1: 01 Series Specifications
Available Target Gas/
Detection Range/
Display Increment
•Ammonia(NH
3): 0 - 75.0 ppm, 0.5 ppm increments
• Chlorine (Cl2): 0 - 3.00 ppm, .02 ppm increments
• Sulphur Dioxide (SO2): 0 - 6.00 ppm, .05 ppm increments
Detection Principle Electrochemical
Sampling Method Diffusion
Response Time 90% in 60 seconds
Accuracy ± 5% of detection range full scale
Indication Digital LCD
Safety/Regulatory
C US
186718
CSA classified, “C/US”, as Intrinsically Safe. Exia. Class I,
Groups A, B, C, & D. Temperature Code T3.
(PENDING)
Power Source Two AA size Alkaline Batteries Standard, Duracell MN1500 or
PC1500
Continuous
Operating Hours At 25 °C: Over 250 Hours, No Alarms or Backlighing
Case High-impact Plastic, Dust and Weather Proof
Standard
Accessories • Belt Clip
• Rubber protective boot
Optional Accessories • Calibration Adapter
• Calibration Kit
• Alligator Clip
• 10 ft. Extender Cable
• Data Logging Kit
Dimensions and
Weight • 2.5” W x 5.2” H x 1.2” D (63 mm x 131 mm x 31 mm)
• 7.6 ounces (215 g)
Operating Temp. &
Humidity 14°F to 104°F (-10°C to +40°C), below 95% RH (non condensing)

SC-01 Operator’s Manual Description • 7
Description
This section describes the components of the SC-01. These components
include the SC-01’s protective rubber boot, case, belt or alligator clip,
sensor retainer, sensor, LCD, control buttons, infrared (IR) communications
port, printed circuit boards, alarm LEDs, buzzer, vibrator, and batteries.
AIR POWER
LCD
Rubber Boot
DISP
Buzzer
Opening
Sensor
Retainer
Sensor
Alarm LEDs
(Behind Lens) RKI
IR Port
Battery Cover
Control
Buttons
Figure 1: SC-01 Component Location

8 • Description SC-01 Operator’s Manual
Protective Rubber Boot
A rubber boot installed over the case helps protects the SC-01. The boot
allows viewing of the display and alarm lights and access to the control
buttons, battery cover, sensor, and belt clip. The sensor must be removed
to remove the protective rubber boot.
Case
The SC-01’s sturdy, high-impact plastic case is radio frequency (RF)
resistant and is suitable for use in many environmental conditions, indoors
and out. It is dust proof and weather resistant.
A clear plastic window through which the LCD can be viewed is located on
the front of the case. A frosted plastic lens above the LCD allows viewing of
the alarm lights. The three control buttons are below the LCD. The left
button is labeled “AIR ▼”, the middle button is labelled “▲DISP” and the
right button is labeled “POWER.” Below the control buttons on the right
side of the front, the buzzer is located inside the case. A hole with a
protective membrane allows the buzzer sound out of the case.
The sensor protrudes out the bottom left of the case. The battery cover is
located to the right of the sensor and allows access to the batteries. The IR
port is located on the right side of the case.
There are two threaded holes on the back of the case. These are used to
mount the belt clip or the optional alligator clip.
Threaded
Inserts
Figure 2: SC-01 Rear View

SC-01 Operator’s Manual Description • 9
Alligator and Belt Clips
The SC-01 is available with two types of clips, the standard belt clip and the
optional alligator clip. Both are illustrated in Figure 3 below.
The belt clip is used to easily clip the SC-01 on a belt. The alligator clip can
be used to attach the SC-01 to clothing or a belt. Teeth in the alligator clip’s
jaws prevent the unit from slipping off.
Sensor Retainer
The sensor retainer is a tubular high impact plastic piece that retains the
sensor in the sensor socket. A rubber guard on the end of the end of the
retainer protects the sensor from impact and an o-ring on the inside and on
the outside of the retainer seal the retainer to the sensor and to the SC-01
case. The end of the retainer is open to allow ambient air to reach the
sensor.
The sensor retainer slides over the sensor into the case and locks in place
with an eighth turn clockwise. Refer to “Replacing the Sensor” on page 37
for instructions to remove and install the sensor retainer.
Alligator
Clip
Belt Clip
Figure 3: Belt & Alligator Clips

10 • Description SC-01 Operator’s Manual
Sensor
The SC-01 is capable of accepting a variety of toxic gas sensors. The
sensor is cylindrically shaped with a multi-pin plug on one end that mates
with the sensor socket in the SC-01 and a diffusion port on the other end
that allows ambient air to reach the sensor. The diffusion port on the end of
the sensor is protected by two plastic ribs in a cross pattern.
The various sensors used in the SC-01 are “smart” sensors. They have
imbedded memory that saves several parameters including the target gas,
detection range, Warning and Alarm setpoints, the most recent calibration
date, and the most recent calibration settings. This allows the SC-01 to
have true plug and play capability. If a calibrated sensor of one type is
exchanged with a sensor in the SC-01 of another type, the SC-01 will be
able to retrieve all the information necessary to monitor for the new target
gas from the new sensor without additional user setup. See “Parts List” on
page 41 for a list of the available sensors.
LCD
The LCD is visible through the front of the case. When the SC-01 is in
Measuring Mode, the target gas concentration, battery condition, and
alarm indications are displayed on the LCD. Various other items are
displayed when the LCD is in other modes, such as Setup Mode. When
either of the three control buttons are pressed, the LCD backlight comes on
for 30 seconds.
Control Buttons
Below the LCD are three control buttons: AIR ▼, DISP ▲, and POWER.
The functions performed by the control buttons are summarized in the
following table:
Table 2: SC-01 Control Buttons
Button Function
AIR ▼
• Turns the LCD back light on.
• Adjusts LCD readings when a fresh air adjustment
is performed.
• Enters Setup Mode with the POWER button.
• Decreases a parameter’s value or changes a
parameter’s setting when a parameter is available
for adjustment in an operational mode.

SC-01 Operator’s Manual Description • 11
Printed Circuit Boards
The primary function of the SC-01 printed circuit boards is to amplify the
signal sent to them from the sensor, convert the signal to a meaningful
measurement of gas concentration, display the gas concentration on the
LCD, store peak gas readings, STEL and TWA values, and activate the
alarm circuit if an alarm point has been reached. They monitor battery
level, battery failure, and sensor failure. They also control the various
operating modes of the unit.
NOTE: The printed circuit boards contain no user serviceable parts.
Alarm LEDs
The SC-01 has four red alarm LEDs. They alert you to gas, low battery, and
sensor failure alarms. They are located on the front of the SC-01above the
display behind a frosted plastic lens.
Buzzer
A solid-state electronic buzzer is mounted inside the SC-01. An opening in
the lower right corner of the case front allows the buzzer’s sound to
emanate from the case. The buzzer sounds for gas alarms, unit
malfunctions, and dead battery alarm. It also serves as an indicator during
normal use of the various LCD display options.
Vibrator
A vibrating motor (vibrator) is mounted inside the SC-01. The vibrator
vibrates momentarily during the power-up sequence and for gas alarms.
▲DISP
• Turns the LCD back light on.
• Enters and scrolls through Display Mode when the
SC-01 is in Measuring Mode
• Increases a parameter’s value or changes a
parameter’s setting when a parameter is available
for adjustment in an operational mode.
POWER
• Turns the unit on and off.
• Turns the LCD back light on.
• Resets the alarm circuit (gas alarms).
• Enters Setup Mode with the AIR button.
Table 2: SC-01 Control Buttons
Button Function

12 • Description SC-01 Operator’s Manual
Batteries
Two AA-size alkaline batteries run the SC-01. At 25°C with no alarms, the
alkaline batteries last at least 250 hours. The battery icon on the LCD
shows remaining battery life.
When the SC-01 detects low battery voltage, a low battery warning is
activated. When battery voltage is too low for normal operation, the SC-01
sounds a dead battery alarm.
The alkaline batteries can be replaced by removing the battery door at the
bottom of the case. See “Replacing the Batteries” on page 36 for
instructions to change the batteries.
WARNING: To prevent ignition of a hazardous atmosphere, batteries
must only be changed in an area known to be
nonhazardous.

SC-01 Operator’s Manual Start Up • 13
Start Up This section explains how to start up the SC-01 and to get it ready for
operation.
Start-up Procedure
1. Press and briefly hold the POWER button until you hear a beep to turn
on the SC-01.
All the alarm LEDs turn on for a few seconds, then the vibrator activates
briefly. While this is happening, all elements of the LCD display and the
LCD backlight turn on for several seconds.
2. If the CAL. LIMIT menu item in Setup Mode is on, then one of the two
following startup sequences takes place. If CAL. LIMIT is turned off, the
startup sequence in Step 3 below takes place. See “Updating the
Calibration Frequency” on page 32 for a description of the CAL. LIMIT.
• If calibration is past due, the following screen appears with “CAL.”
flashing and the LEDs and buzzer pulsing several times alerting you
that the SC-01 is due for calibration. If this screen appears, wait for
the buzzer and LED pulsing to stop, then press and release the
POWER button to continue in the startup sequence.
The SC-01 will then show the current date, current battery voltage,
detection range full scale, and the alarm point settings before
proceeding to Measuring Mode and beeping twice.
• If the calibration is up to date, the SC-01 then displays the
calibration due date, how many days until the next calibration,
current date, current battery voltage, detection range full scale, and
the alarm point settings before proceeding to Measuring Mode and
beeping twice.
3. If the CAL. LIMIT menu item in Setup Mode is turned off, the SC-01
shows “WARMUP” in the upper left of the LCD for a few seconds, the
displays the current date, current battery voltage, detection range full
scale, and the alarm point settings before proceeding to Measuring
Mode and beeping twice.
CAL. LIMIT
CAL.

14 • Start Up SC-01 Operator’s Manual
CAUTION: If the instrument gives a low battery warning or dead battery
alarm, change the alkaline batteries before using the
instrument. See “Alarm Indications” on page 17 for a
description of the battery alarm indications.
4. The SC-01 is now operating in Measuring Mode and the concentration
of the target gas is displayed on the LCD. The backlight turns off after
30 seconds.
Performing a Fresh Air Adjustment
Before using the SC-01, set the fresh air reading. Performing this
adjustment ensures accurate gas readings in the monitoring environment
the calibration is current.
1. Find a fresh air environment, an environment of normal oxygen content
(20.9%) that is free of toxic or combustible gasses.
2. With the unit on and in Measuring Mode, press and hold the AIR ▼
button. The LCD displays “hold” prompting you to hold the AIR ▼button
3. After a moment, the LCD will indicate “Adj.”. Continue to hold the AIR ▼
button.
SO20.00
PPM
AIR CAL
h o l d
AIR CAL
Adj.

SC-01 Operator’s Manual Start Up • 15
4. Release the AIR ▼button when the LCD displays “RELEASE” in the
upper left corner.
5. The unit will take a few seconds to set the reading to 0 ppm, then
indicate “FINISH” in the upper left corner of the LCD and return to
Measuring Mode.
Turning Off the SC-01
1. Press and hold the POWER button for about five seconds to turn off the
unit. The buzzer will sound while the POWER button is being pressed
before the unit turns off.
2. Release the button when the LCD indicates “GOOD-BYE” in the upper
right corner.
RELEASE
Adj.
GOOD-BYE

16 • Operation in Measuring Mode SC-01 Operator’s Manual
Operation in Measuring Mode
This section covers the operation of the SC-01 in Measuring Mode. It
explains Normal Operation, Display Mode, and alarm indications.
Normal Operation
When the SC-01 comes out of its startup sequence, see “Start Up” on
page 13, it is in normal operation if no alarm indications are taking place. It
is advisable to perform a fresh air adjustment when the SC-01 comes out
of its startup sequence as described in “Start Up”.
In the Normal Operation screen of Measuring Mode, the battery level,
target gas, and target gas concentration are displayed on the LCD. The
battery icon has three bars visible when the batteries have a full charge. As
the battery charge decreases, the bars will gradually disappear, one by one
from left to right.
Display Mode
You can access Display Mode when in Measuring Mode by using the
▲DISP button. In Display Mode you can view the detection range full
scale, peak reading, the STEL value, and the TWA value, the date and
time, and the amount of datalogging time remaining. STEL is an acronym
for short-term exposure limit, and it is the average reading of the target gas
during the last 15 minutes. TWA is an acronym for time-weighted average,
and it is the average reading for the target gas during the last eight (8)
hours. If eight (8) hours has not elapsed since the unit was turned on, the
TWA is still calculated over eight hours, with the missing time assigned a
zero (0) value for the readings. Similarly, if the unit has not been on for 15
minutes, the missing time is assigned a 0 value and the STEL is calculated
over 15 minutes. The peak reading, STEL value, and TWA value are
cleared when the unit is turned off.
To view the various items in Display Mode, do the following:
1. Make sure the SC-01 is in Measuring Mode. The SC-01must be in
Measuring Mode for you to access Display Mode.
Figure 4: LCD in Measuring Mode
SO20.00
PPM

SC-01 Operator’s Manual Operation in Measuring Mode • 17
2. Press and release the ▲DISP button to enter Display Mode. The LCD
backlight will activate and the LCD will display the detection range full
scale value.
3. Press and release the ▲DISP button again to proceed to the PEAK
Screen. The LCD displays the peak gas reading since the SC-01 was
turned on.
4. Press and release the ▲DISP button again to proceed to the STEL
Screen. The LCD displays the STEL value.
5. Press and release the ▲DISP button again to proceed to the TWA
Screen. The LCD displays the TWA value.
6. Press and release the ▲DISP button again to proceed to the Date/
Time Screen. The LCD displays the current date and time.
7. Press and release the ▲DISP button again to proceed to the Log
Remaining screen. The LDC displays how much datalogging time
remains.
8. Press and release the ▲DISP button once again to return to the unit to
Measuring Mode.
NOTE: If you do not press a button for 20 seconds while in Display Mode,
the SC-01will return to Measuring Mode automatically and the
backlight will turn off 30 seconds since the last button was
pressed.
Alarms
This section covers alarm indications. It also tells you how to reset the SC-
01 after an alarm has occurred and how to respond to an alarm condition.
See Table 4 on page 32 for the standard alarm point settings.
Alarm Indications
The SC-01 will sound an alarm, flash its alarm lights, and vibrate when the
target gas concentration rises above the Warning level. The SC-01 also
sounds an alarm, flashes its alarm lights, and vibrates when the Alarm level
is reached. In addition, the SC-01 has a low battery warning, a dead
battery alarm, an over range alarm, a sensor failure alarm, and a system
failure alarm. See Table 3 below for a description of each alarm indication.

18 • Operation in Measuring Mode SC-01 Operator’s Manual
Table 3: Alarm Types and Indications
Alarm Type LCD Indications Other Indications
Warning
Concentration of gas
rises above the
Warning level.
• Gas reading
flashes.
• Back light turns on.
• Pulsing tone
alternates with
alarm LEDs
flashing once per
second.
• Unit vibrates once
per second.
Alarm
Concentration of gas
rises above the Alarm
level.
• Gas reading
flashes.
• Back light turns on.
• Pulsing tone
alternates with
alarm LEDs
flashing twice per
second.
• Unit vibrates twice
per second.
TWA or STEL
Concentration of
target gas rises above
the TWA or STEL
alarm point.
• Back light turns on.
• Gas reading
flashes
•TWA or STEL
replaces the gas
name in the upper
left of the LCD.
• Pulsing tone once
per second
• Unit vibrates once
per second
• Alarm LEDs flash
once per second.
Over Range
Concentration of gas
rises above the full
scale of the SC-01.
(Or there could be a
problem with the unit.)
• Gas reading
replacedbyblinking
brackets.
• Back light turns on.
• Gas name in upper
right of display
replaced by OVER
• Pulsingtoneoccurs
once per second.
• Unit vibrates once
per second.
• Alarm light flashes.
Low Battery Warning • Last remaining bar
on the right in
battery icon
flashes.
•None
Dead Battery Alarm • Gas name and
readingreplacedby
BATTERY FAIL.
• Battery icon
flashes.
• Quick pulsing tone
and LED flashing.

SC-01 Operator’s Manual Operation in Measuring Mode • 19
Resetting Gas Alarms
To reset a gas alarm, press and release the POWER button after the gas
reading falls below the Warning level. If a TWA or STEL alarm has been
activated, it cannot be reset unless you turn off the unit.
NOTE: Even though the gas concentration may have returned to normal
or may have fallen below the low alarm point, the alarm
indications will continue until you have reset the alarm using the
POWER button.
Responding to Alarms
This section describes response to gas, over range, battery, sensor failure,
and system failure alarms.
Responding to Gas Alarms
1. Follow your established procedure for an increasing gas condition.
2. Reset the alarm by pressing and releasing the POWER button after the
alarm condition has been cleared.
Responding to an Over Range Alarm
WARNING: An over range condition may indicate an extreme toxic
gas concentration. Confirm the gas concentration with a
different SC-01 or with another gas detecting device.
1. Follow your established procedure for an increasing gas condition.
2. Reset the alarm by pressing and releasing the POWER button after the
alarm condition has cleared.
3. Calibrate the SC-01 as described in “Maintenance” on page 34.
Sensor Failure • Gas name and
readingreplacedby
SENSOR FAIL.
• Quick pulsing tone
and LED flashing.
System Failure • Gas name and
readingreplacedby
CIRCUIT FAIL.
• Quick pulsing tone
and LED flashing.
Clock Failure • Gas name and
readingreplacedby
CLOCK FAIL
• Quick pulsing tone
and LED flashing.
Table 3: Alarm Types and Indications
Alarm Type LCD Indications Other Indications

20 • Operation in Measuring Mode SC-01 Operator’s Manual
4. If the over range condition continues, you may need to replace the
sensor.
5. If the over range condition continues after you have replaced the
sensor, contact RKI Instruments, Inc. for further instructions.
Responding to Battery Alarms
WARNING: The SC-01 is not operational as a gas monitoring device
during a dead battery alarm. Take the SC-01 to a non-
hazardous area and change the alkaline batteries as
described in “Replacing the Batteries” on page 36.
The SC-01 is fully functional in a low battery warning condition. However,
only about eight hours of operation may remain depending on certain
conditions such as alarm occurrences and how often the backlight comes
on.
NOTE: Alarms and the back light feature consume battery power and
reduce the amount of operating time remaining.
When a low battery warning occurs, change the batteries as soon as
possible. See “Replacing the Batteries” on page 36” for instructions to
change the batteries.
Responding to a Sensor Failure Alarm
1. Try to calibrate the SC-01 as described in “Performing a Fresh Air
Adjustment” on page 26 and “Performing a Span Adjustment” on
page 27 before replacing the sensor.
2. If the sensor failure continues, replace the sensor as described in
“Replacing the Sensor” on page 37.
3. If the sensor failure condition continues after you have replaced the
sensor, contact RKI Instruments, Inc. for further instructions.
Responding to a Circuit Failure Alarm
1. If a circuit failure occurs, try turning the unit off then on again.
2. If the unit remains in circuit failure, contact RKI Instruments, Inc. for
further instructions.
Responding to a Clock Failure Alarm
1. If a clock failure occurs, try turning the unit off then on again.
2. If the unit remains in clock failure, contact RKI Instruments, Inc. for
further instructions.