Sentry ST313A User manual

ST313A
Combustible
Gas Detector
Instruction Manual
Ver.01_202211121

1. Introduction-------------------------------------------1
1-1. Features ----------------------------------------------1
1-2. Applications-----------------------------------------1
2. Safety Information--------------------------------1
2-1. Safety symbols-------------------------------------2
2-2. Warning---------------------------------------------3
3. Product Specifications--------------------------4
4. General Descriptions----------------------------5
4-1. Parts and Control Panel-------------------------5
4-2. Main Function-------------------------------------6
4-2-1 Button Function-----------------------------------6
4-2-2 Low Battery Indicator--------------------------10
4-2-3 Sensor Failure Indicator -----------------------10
4-3. Inspection Before use--------------------------10
5. Maintenance---------------------------------------11
5-1. Leak Test Bottle---------------------------------11
5-2. Replacement Parts -----------------------------11
5-3. Lithium Battery Storage and Care ----------12
5-4. Charging the Lithium Battery----------------14
5-5. Clean ----------------------------------------------16
5-6. Trouble Shooting------------------------------16

1
1.Introduction
Thank you for purchasing the combustible gas
detector.
Read through this instruction manual before operating
the unit.
Please also store and retain this instruction manual for
future reference.
1-1.Features
●LED Tip light
●Mute function
●Reset Indicator
●LED charging Indication
●Low battery indicator
●Rugged flexible probe
●Sensor failure indicator
●USB power adaptor
●3 adjustable sensitivity levels
●DC 3.7v rechargeable lithium battery
●Extremely sensitive semiconductor sensor
●Multiple colors LCD display for leak level indictor
●Detects methane, propane, butane, and other
hydrocarbons gas detections.
●Automatic adjustment and reset to background
●Microcontroller circuitry that guarantees accuracy
and reliability
1-2. Applications
●Industrial flammable gas detections
●Laboratory accurate
●Systems engineering
●Semiconductor production
●Automotive service
●Aircraft construction industry

2
2. Safety Information
Read the following safety information carefully before
attempting to operate or service the meter.
Only qualified engineer should perform repairs.
2-1. Safety symbols
◇Certification
This instrument conforms to the following standards:
EN61326-1:2021 : Electrical equipment for
measurement, control and
laboratory uses equipment EMC
test.
IEC61000-4-2 : ESD immunity test.
IEC61000-4-3: Radiated, radio-frequency,
Electromagnetic field immunity test.
IEC61000-4-8 : Power frequency magnetic field
immunity test.
◇
Restrict to use of 10 substances within electrical and
electronic equipment (EEE), thereby contributing to
the protection of human health and the environment.
◇REACH（SVHC）
The device of used materials contents no following
substances that list of proposed REACH substances of
very high concern.
◇WEEE
The device may not be disposed of with the
trash. It promotes the re-use recycling and other
forms of recovery of used materials and
components, and to improve the environmental
performance of all operators (manufacturers, traders,
and treatment facilities) involved in the life cycle of
products. Dispose of the product appropriately in
accordance with the regulations in force in your
country.

3
2-2. Warning
Please read the manual carefully to ensure safe and
correct use of this meter before using.
Please re-read if necessary.
Be sure to adhere to the following points to avoid
injury.
●Please be aware of this meter is not water-proof
product.
●Do not attempt to replace the sensor and LED.
●Do not attempt to repair it yourself if the meter is
malfunction.
Only qualified engineer may do it.
●Do not force to bend the flexible probe over its limit
of angle.
●Do not subject the probe tip to impact that could
break the inside sensor.
●Do not use the meter in places where flammable or
nearby the fire.
●Do not use this meter in environments outside this
range: 32°F (0°C) to 122°F (50°C)
●Never use organic solvents to clean the meter. (Such
as thinner, benzene, etc.)

4
3. Product Specifications
Model ST313A
Sensor Semiconductor
Detection Gases
Methane, Propane, Butane, and other
hydrocarbons gases
Sensitivity levels
High : 10PPM
Medium : 30PPM
Low : 100PPM
Calibration Manually reset to background level
Response time Less than 0.5 second
Warm up time Approx. 50 seconds
Battery type
3.7V DC, 1960mAh rechargeable
lithium battery
Battery life
Max. up to10 hours continuous use
after fully charged.
Sensor failure
notification
Yes
Audio alarm Yes(Buzzer)
Auto power off 10 minutes of idle.
Low battery
indicator
Yes (Battery Icon)
Tip light Yes
Flexible probe
length
18” (450mm)
Operating temp.
and %RH
32°F ~ 122°F(0°C ~ 50°C), ＜80%RH
Storage temp.
and %RH
14°F ~ 140°F(-10°C ~ 60°C), ＜70%RH
Dimensions 7.2”x 2.8”x 1.6” (184 x 70 x 40 mm)
Weight 12 oz.(340g)
Accessories
Included: Quick user's guide, USB
cable, Leak test bottle
Option to buy: Charger, Rubber
protector, Hard carrying case.

5
4. General Descriptions
4-1. Parts and Control Panel
①
Power Button
②Sensitivity Level Indicator
③Leak Level Indicator
④Sensor failure Indicator
⑤Low Battery Indicator
⑥Charging Indication
⑦Reset Button
⑧Tip Light LED ON/OFF
Button
⑨Back Light ON/OFF
Button
⑩
Reset/Back Light Indicator
⑪Reset Indicator
⑫Mute Indicator
⑬Buzzer Output
⑭Mute Button
⑮Sensitivity Button
(High, Medium, Low)
⑯Flexible Probe
⑰Tip Light

6
4-2. Main Function
4-2-1 Button Function
【 】Power Button
●Turn ON:
Press and hold the Power button for 2 seconds to
turn the detector on.
LCD screen will be lit with the start-up buzzer beep
(or no buzzer beep under MUTE mode).
●Turn OFF:
Repeat to press and hold the Power button for 2
seconds again to turn the detector off.
●Warm-Up:
The detector will automatically start heating the
sensor after power-on.
During the warm-up, the graphical Leak Level will be
flashed.
After the warm-up, the leak level return to the lowest
point, and the buzzer beeps every 2 seconds (or no
buzzer beep under MUTE mode).
At this time the detector is ready to find leaks.
Warm up time takes approx. 50 seconds.

7
【 】Sensitivity Button
Press the Sensitivity button to change sensitivity.
High, Medium or Low sensitivity level is signed by its
respective icons , and .
※The detector will automatically default to previous
sensitivity level after the warm-up.
【 】RESET Button
Press the Rest button once and the Reset Indicator
on screen flashes 1 sec., the detector now reset to
background level manually.

8
【 】MUTE Button
●Press the Mute button to toggle the audio alarm on
and off.
The buzzer alarm is turned off: The MUTE icon
will be appeared.
The buzzer alarm is turned on: The MUTE icon
will be off.
※The detector will automatically default to previous
MUTE ON/OFF setting after re-start.
●The buzzer alarm is OFF
Under the MUTE mode, all audible beeps are off.
◆The buzzer alarm is ON
Button Tone
The buzzer gives one beep when any of button is
pressed.
◆Detection Tone
The buzzer beeps every 2 seconds when no leak
activity is found.
The buzzer becomes rapid when leak signal is
approaching.
The fast beeps are given, the high-density
combustible gas is detected.
◆Sensor Failure Indicator
The sensor failure icon blinks and gives slow
beep alarm when sensor was misplaced or failure.

9
【 】Backlight ON/OFF Button
The backlight mode has 2 kinds, Auto backlight Mode
and Manual backlight Mode. The factory default value is
under Auto backlight Mode.
Press and hold the Backlight Button for 2 seconds to
toggle to the Auto/Manual backlight mode.
●Auto backlight Mode (Power-saving Mode)
When no leak activity is found and no button is
pressed within 30secs, the detector will enter Auto
backlight Mode (Power-saving Mode) to shutdown
LCD backlight. And the backlight will be activated
again after finding leak activity or pressing any
buttons.
※When detector enters Auto backlight Mode (Power-
saving Mode), pressing Backlight Button again,
the detector will lit up the backlight on screen.
◆Auto backlight Mode: pressing and hold Backlight
Button for 2 secs, and will show on
screen for 2 secs and the detector has enter Auto
backlight Mode.
●Manual backlight Mode
Under Manual backlight mode, pressing Backlight
Button to toggle backlight ON/OFF.
◆Manual backlight Mode : pressing and hold
Backlight Button for 2 secs, and
will show on screen for 2 secs and the detector has
enter Manual backlight Mode.

10
【 】Tip Light LED Button
The tip light is always off after re-start.
Press the Tip Light LED Button to turn on/off the light of
probe tip.
4-2-2 Low Battery Indicator
When the LOW-BATT icon is appeared：
Read the warning in the section 5-3 carefully and
charge the battery by section 5-4.
If the battery capacity is too low, the detector will
automatically turn off to protect the lithium battery
and electronics.
4-2-3 Sensor Failure Indicator
The sensor failure icon blinks and gives slow
beep alarm when sensor was misplaced or failure.
Please replace a new sensor by section 5-2 or contact
your dealer.
4-3. Inspection Before use
1. Before operation, please make sure that the
environment is ventilated and no dust on top of
probe.
2. Make sure that there are no factors may cause fire or
explosion at the testing area.
3. Power on the detector and wait for the warm-up step
is finished, then change the sensitivity level to the
high-sensitivity mode.
4. Using the test bottle to test the detector about 0.5
seconds. When the leak activity is found, it means
that the sensor and electronic circuit are working
correctly.
5. If no leakage is found, please check the chapters 5-6
for trouble shooting.

11
5. Maintenance
5-1 Leak Test Bottle
Remember to close the seal cap of leak test bottle to
avoid evaporating completely after test.
5-2. Replacement Parts
●Sensor
●DC 3.7 V rechargeable lithium battery
Replacement of the sensor or Tip Light LED (3V) is
shown in the following figure:
Assemble the sensor on the same side as the raised
point of the sensor seat.
Note: Turn off the detector before removing sensor.
1. The life of sensor is 1 year (normally use).
2. Please mind there is no water drops, dusts in the
surface of sensor.

12
5-3. Lithium Battery Storage and Care
Operating Temperature and Humidity:
Discharge: 32°F ~ 122°F (0°C ~ 50°C), less than 80% RH
Charging: 32°F ~ 113°F (0°C ~ 45°C), less than 80% RH
Storage Humidity: Less than 70% RH
Storage temperature and capacity recovery:
Temperature range
Duration
Capacity recovery
-4°F ~ 139°F (-20°C ~ +60°C) 1month 75％
-4°F ~ 113°F (-20°C ~ +45°C) 3months 70％
-4°F ~ 77°F (-20°C ~ +25°C) 1year 80％
In case of contacting the materials from the battery:
Skin Contact: Washing immediately with water and
soap.
Eye Contact: Washing immediately with plenty of water
for at least 15 minutes.
Get medical attention.
Ingestion: Get medical attention immediately.
Warning:
●When the battery has rust, bad smell or something
abnormal at first time-using, do not use and contact
your dealer.
●The battery is requested to be stored within a proper
temperature range specified in this specification.
●Do not disassemble or reconstruct battery.
●Do not give battery impact or fling it.
●Do not immerse the battery in water or sea water or
get it wet.
●Do use the specified charger and observe charging
requirement.
●Do not continue to charge battery over specified time.
●Do not charge the battery near a fire or in a hot
vehicle or direct sunlight.

13
●Do not use the battery with conspicuous damage or
deformation.
●Charging temperature range is regulated between
32°F ~ 113°F(0°C ~ 45°C).
Do not charge the battery out of recommended
temperature range.
Charging out of recommended range might cause the
generating heat or serious damage of battery.
And it might cause the deterioration of battery's
characteristics and cycle life.
●Do not use or leave batter nearby fire, stove, or
heated place.
The battery may generate heat, smoke, or flame.
And it might cause the deterioration of battery’s
characteristics or cycle life.
●Avoid discharging the battery completely, it can
damage the performance of the battery.

14
◇
5-4. Charging the Lithium Battery
The detector will automatically turn off if the battery
capacity is too low, charging it when the LOW-BATT LED
is lit.
It is highly recommended not to use the detector during
charging, the battery may be heated and dangerous.
The CHARGING LED be lit red color during charging, it
will turn to green when charging is completed.
Note: Always charge within the charging environment
specifications of 32°F~113°F (0°C~45°C), less than 80%
RH.
The lithium battery is charged with AC power via AC
adapter and USB cable:
(AC adapter/charger is not include)
1. Use the AC adapter and plug mini B male into the
mini B receptacle of the unit (Fig. 1).
2. Plug the AC adapter to the wall jack (Fig. 2).
3. Use the USB cable plug mini B receptacle of the unit
and plug A male into PC or Notebook USB port (Fig. 3).

15

16
5-5 Clean
Clean the Housing:
Never use organic solvents to clean the meter. (Such as
thinner, benzene, etc.)
Warning:
The organic solvents might damage the sensor, please
avoid the solvents contacts the sensor.
5-6. Trouble Shooting
1. When the detector cannot turn on：
Please refer to chapters 5-3 and 5-4 and make sure
that the lithium battery is fully charged.
Please contact your dealer if it still cannot be turned
on after charging
2. LCD display is failed to show:
Please refer to chapter 4-2-1 for the description of
backlight function and make sure which backlight
mode you would like to choose.
Please contact your dealer if LCD display is failed to
show any sign in screen.
3. No response when using leak test bottle for leak
detection test:
Please move to32°F~122°Foperating environment.
Please refer to chapter 5-1 for instructions to check
that the leak test bottle is in good condition.
Please refer to chapter 5-2 to check that the sensor is
placed correctly
Please refer to chapter 5-2 for instructions to replace
the sensor or contact your dealer.

PA05-000312A-01 Ver. 01 22/Nov
SENTRY OPTRONICS CORP
3F, No. 122, Sec. 1, Sanmin Road, Ban-Ciao
Dist., New Taipei City 220, Taiwan R.O.C.
TEL: [phone]
FAX: [phone]
www.sentrytek.com.tw