Triplett GSM400 User Manual

User Manual

GSM400

CO2 Meter with RH% and Temperature

Introduction

Congratulations on your purchase of the Triplett GSM400 CO2 Meter with RH% and Temperature.
This meter measures CO2 (Carbon Dioxide) levels, air temp., dew point, wet bulb temperature and
humidity and is an ideal instrument for indoor air quality (IAQ) diagnosis.

Description

METER DESCRIPTION

1. Temperature and Humidity Sensor

2. CO2 Sensor (Rear)

3. LCD Display

4. AC Adaptor Connector

5. RS-232 Port

6. Keypad

7. Battery Compartment (Rear)

LCD DISPLAY

O

%

1. CO2 concentration in ppm

2. Relative Humidity in %

3. Air Temperature, Dew Point or Wet Bulb Temperature

SYMBOLS

TWA Time weighted average (8 hours)
STEL Short-term exposure limit (15 minutes
weighted average)
HOLD Freezes current reading on display
MIN/MAX Minimum/Maximum readings

DP Dew point temperature
AIR Air temperature
WBT Wet bulb temperature
% Unit of relative humidity
C or F Celsius/Fahrenheit

Low battery indicator

BATTERY INSTALLATION

The meter is powered by 4 AA batteries or a DC adaptor. Install the batteries into the rear battery
compartment observing correct polarity. When an adaptor is used, the batteries will be disconnected
from the meter. The adaptor cannot be used as a battery charger. When the battery voltage drops
below the required level, and “Lob” will appear on the display, a beeper sounds and readings

are no longer displayed. (Press any key but the SET to stop the beeps). Replace the batteries to
resume normal operation.

CO2

You, as the end user, are legally bound (EU Battery ordinance) to return all used
batteries, disposal in the household garbage is prohibited! You can hand over your
used batteries / accumulators at collection points in your community or wherever batteries
/ accumulators are sold!

Disposal: Follow the valid legal stipulations in respect of the disposal of the device at
the end of its lifecycle

Operation

POWER ON/OFF

Press SET to turn the meter on and off. At power up, the meter emits a short beep and performs a
30 second countdown for meter warm up. It then enters the normal operation mode with current
CO2, temperature and humidity readings displayed.

CO2

%

O

TAKING MEASUREMENT

The meter starts measurements when powered on and updates readings every second. If the
operating environment changes (ex. from high to low temp.), it takes 30 seconds for CO2 sensor to
respond and 30 minutes for RH.

NOTE: Do not hold the meter close to your mouth or any other source of CO2.

AIR, DP and WBT Measurements

Press the DP/WBT button to switch temperatures display. The lower left display will cycle from

“AIR” air temperature, “DP” dew point temperature and “WBT” wet bulb temperature.

DATA HOLD

Press the HOLD button to freeze the readings, the "HOLD” icon is displayed on the left top of the

display. All current readings are held unchanged, except STEL and TWA. Press “HOLD” again to

cancel the hold function.

BACKLIGHT

Press the MODE/▲ button for more than 1 second to activate or to cancel backlight function.

MIN,MAX,STEL,TWA

In the normal mode, press the Max/AV button to see the minimum, maximum, and weighted
average readings. With each press of the Max/AV button, the meter displays MIN, MAX,
STEL, TWA in sequence and then returns to the normal mode.

In MIN and MAX modes, the meter shows the minimum and maximum readings of CO2 (main
display), AIR, DP or WB temperatures (lower left display) and Humidity (lower right display).

In STEL and TWA modes, the main display shows the weighted average of CO2 readings for the
past 15 minutes (STEL) or 8 hours (TWA). The lower displays are the current measurements

STELCO2

%

O

NOTE:

8. If the meter has been powered on for less than 15 minutes, the STEL value will be the
weighted average of readings taken since power on. As well, the TWA
mode will display a weighted average of readings prior to 8 hours of
operation.

9. The GSM400 takes at least 5 minutes to calculate STEL and TWA. The
display shows “----”
during the first 5 minutes from power on.

3. The STEL and TWA values will keep updating every 5 minutes.

ALARM

The meter features an audible alarm to give warnings when CO2 concentration exceeds the set
limit. It emits beeps (Abt.80dB) when CO2 level goes over the set value and stops when any key
(except SET) is pressed or the readings fall below the set value. It beeps again if the value
exceeds the limit. Restart the meter if the beeper will not stop.

AUTO POWER OFF

The meter turns off automatically after 20 minutes of inactivity. To override the function, press and
hold down the SET and HOLD buttons until “n” appears in the display (approx. 2 seconds) while
turning on the meter on. NOTE: Auto sleep function will be disabled during calibration mode.

SETUP (alarm limit and temperature scale)

In the normal mode press and hold the SET button for more than 1 sec to enter the setup mode.
To exit the setup mode, press the CAL/Esc button when either P1.0 or P3.0 is displayed.

P1.0 CO2 ALARM Limit

When entering setup mode, P1.0 and “AL” are displayed.
Press the MN/AV button to scroll to P1.1 for setting CO2 alarm threshold. The current CO2

set value will be blinking.

Press the MODE/▲ button to increase or the DP/WBT/▼ button to decrease the value. Each
press adjusts 100 ppm. The alarm range is from 100 to 9900ppm. When the preferred alarm
value is set, press the MN/AV button to exit and save the setting or the CAL/Esc button to exit
without saving and return to P1.0.

P3.0 TEMPERATURE SCALE

Press the MODE/▲ button or the DP/WBT/▼ button in P1.0 to access P3.0 for setting
the temperature scale.
Press the MN/AV button to go into P3.1 for setting the temperature units. The currently selected
units (°C or °F) will be blinking in the display. To switch units, press the MODE/▲ button. Press
the MN/AV button to save the setting or press the CAL/Esc button exit without saving and return
to P3.0.

Calibration

CO2 CALIBRATION

The meter is calibrated to a standard 400ppm CO2 concentration at the
factory

CAUTION: Do not calibrate the meter in an atmosphere of unknown CO2
concentration.

1. Place the meter in the 400ppm calibration chamber. Turn the

RH CALIBRATION

meter on
and hold down the CAL/Esc and MODE/▲
buttons simultaneously to enter CO2

calibration mode. 400ppm and “CAL” will

blink on the LCD while performing
calibration.

2. Wait about 5 minutes until the blinking
stops. The calibration is then completed
and the meter automatically returns to the
normal mode.

NOTE: Ensure the batteries are fresh prior to calibration to

prevent an interruption or failed calibration.

The meter is calibrated to a standard 33% and 75% salt solution bottle.
CAUTION: Do not calibrate the humidity without the default calibration

salt. Otherwise, permanent damage could occur. Contact the Triplett for
calibration salts or services.

33% calibration

1. Plug the sensor probe into 33% salt bottle.

2. In the normal mode, Press and Hold the
CAL/Esc and DP/WBT/▼ buttons to enter the

33% calibration. “CAL” and calibrating value

(32.7% if at 25°C) will blink on the LCD with
current temperature at the left.

3. The meter is now calibrating, and will finish

in about 60 minutes when “CAL” and

humidity stop blinking.

75% calibration

1. After the 33% calibration, plug the sensor probe into a 75% salt

bottle.

2. Press the MN/AV button to enter 75% calibration.

3. “CAL” and calibrating value (75.2% if at
25°C) will blink on the LCD with current
temperature at the left.

4. The meter is now calibrating. Wait about 60 minutes until the
blinking
stops, then calibration is completed and the meter will return to
normal mode.

NOTE: Single point calibrations are allowed. To calibrate 33% only, press

CAL/Esc and exit when 33% calibration is completed. To
calibrate 75% only, press MODE/▲ within the 5 minutes while
initializing 33% calibration.

Specifications

Function

Range

Resolution

Accuracy

0 to 5000ppm

1ppm

±(%5rdg + 30ppm)

CO2

5000 to 9999ppm

1ppm

Not specified

Pressure dependence: +1.6% reading per kPa deviation
from

normal pressure, 100kPa

Temperature

-10 to 60°C

0.1°

±0.6°C/0.9°F

14 to 140°F

Humidity

0.0 to 99.9%

0.1%

±3%(10 to 90%)

±5%(< or > 10 to 90%)

Wet Bulb

-5 to 60°C

0.1°

23 to 140°F

Calculated from RH
and

Dew Point

-20 to 60°C

0.1°

Temperature

-4 to 140°F

Display

Triple LCD with backlight

Sensor Type

CO2: NDIR (non-dispersive infrared) technology

Humidity: Capacitance sensor;

Temperature (air):
Thermistor

Operating Conditions

0 to 50oC (32 to 122oF); < 95% RH non­condensing

Storage Conditions

-20 to 60oC ( -4 to 140oF); <99% RH non­condensing

Power Supply

4 x 1.5V ‘AA’ batteries or AC adaptor (9V/1A)

Battery Life

approx. 24 hours (alkaline batteries)

Dimensions / Weight

200x70x57mm (7.9x2.7x2.3”)/190g (6.7 oz.)

Maintenance

CLEANING AND STORAGE

1. The meter should be cleaned with a damp cloth and mild detergent
when necessary. Do not use solvents or abrasives.

2. Store the meter in an area with moderate temperature and humidity
(refer to the operating and storage range in the specifications chart
earlier in this manual).

TROUBLESHOOTING

Can’t power on

Press SET for more than 0.3 seconds and try again. Check that the
batteries have good contact and the correct polarity or that the AC
adaptor is properly connected.

Slow response

Check whether the air flow channels on the rear of the meter are blocked.

Error messages

E01: CO2 sensor damaged.
E02: The value is under range.
E03: The value is over range.
E04: The original data error results in this error (DP, WB)
E07: Too low voltage to measure CO2, replace batteries or use an
adaptor.
E11: Retry humidity calibration.
E17: Retry CO2 calibration.
E31: Temperature sensor damaged.
E34: Humidity sensor damaged.

CO2 Levels and Guidelines

Non-Enforced Reference levels:

250 - 350 ppm – background (normal) outdoor air level

350- 1,000 ppm - typical level found in occupied spaces
with good air exchange. 1,000 – 2,000 ppm - level
associated with complaints of drowsiness and poor air.
2,000 – 5,000 ppm – level associated with headaches,

sleepiness, and stagnant, stale, stuffy air. Poor concentration,
loss of attention, increased heart rate and slight nausea may also
be present.
>5,000 ppm – Exposure may lead to serious oxygen deprivation
resulting in permanent brain damage, coma and even death.

Regulatory exposure limits:

ASHRAE Standard 62-1989: 1000ppm: CO2 concentration in
occupied building should not exceed 1000ppm.

OSHA: 5000ppm: Time weighted average over five 8-hour
work days should not exceed 5000ppm

Building bulletin 101 (Bb101): 1500ppm. UK standards for schools
say that CO2 at averaged over the whole day(i.e. 9am to 3.30 pm)
should not exceed 1500ppm.

Germany, Japan, Australia, UK...: 5000ppm, 8 hours
weighted average in occupational exposure limit is 5000ppm

Warranty

Triplett / Jewell Instruments extends the following warranty to the original purchaser of
these goods for use. Triplett warrants to the original purchaser for use that the products
sold by it will be free from defects in workmanship and material for a period of (1) one
year from the date of purchase. This warranty does not apply to any of our products
which have been repaired or altered by unauthorized persons in any way or purchased
from unauthorized distributors so as, in our sole judgment, to injure their stability or
reliability, or which have been subject to misuse, abuse, misapplication, negligence,
accident or which have had the serial numbers altered, defaced, or removed.
Accessories, including batteries are not covered by this warranty

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www.triplett.com