Triplett GSM450 User Manual

User Manual

GSM450

CO/CO2 Meter with RH% and Temperature

Introduction

Thank you for selecting the Triplett GSM450 Meter. The GSM450
measures CO2 (Carbon Dioxide) levels, CO (Carbon Monoxide) levels,
air temperature, and relative humidity. The GSM450 also displays dew
point and wet bulb temperatures, generated from calculations performed
on temperature and humidity measurements. The GSM450 is an ideal
instrument for indoor air quality (IAQ) analysi

Features

 Adjustable carbon monoxide warning level
 Designed with NDIR (non-dispersive infrared)
 Long life electrochemical sensor
 Audible and visual alarm
 Backlit LCD for easy viewing in dimly lit areas
 Low battery indicator
 Auto power off
 Mini USB connector
 Manual and automatic recording

Safety Information

IMPORTANT CARBON MONOXIDE (CO) SAFETY NOTES

1. The GSM450 Carbon Monoxide Monitor is intended for general
purpose Air Quality monitoring only, and has not been certified for use
pursuant to any state or city safety Carbon Monoxide Alarm or
Monitoring requirements.

2. The GSM450 Carbon Monoxide Monitor has not been tested by an
independent lab to comply with the UL 2034 or IAS 6-96 standard.

3. It is the responsibility of the customer to obtain and apply current
local, state, and national regulations with regard to CO alarms,
monitoring and testing.

4. Electromagnetic (EMI) interference my cause erratic meter readings;
do not place meter near areas of high EMI when taking CO
measurements.

5. Recovery time is required after the meter has been exposed to high
levels of CO; the longer the exposure, the longer the recovery time.

Carbon monoxide is life threatening even at relatively
low concentrations; learn and recognize the effects of
CO poisoning (see Table below). Do not use this meter
as a personal safety-monitoring device

Effects of Carbon Monoxide (CO) poisoning

0-1 PPM

Normal background levels

9 PPM

Maximum allowable short term exposure

50 PPM

Maximum allowable continuous exposure level in any
8-hour

period, according to OSHA

200 PPM

Mild headache, fatigue, nausea and dizziness after 2­3 hours

400 PPM

Frontal headache with 1-2 hours, life threatening
after 3 hours

800 PPM

Dizziness, nausea, convulsions within 45 minutes.
Unconsciousness

within 2 hours. DEATH WITHIN 2 TO 3 HOURS

1600 PPM

Headache, dizziness, nausea within 20 minutes,

DEATH WITHIN 1

HOUR

3200 PPM

Headache, dizziness, nausea within 5-10 minutes.

DEATH WITHIN

25-30 MINUTES

6400 PPM

Headache, dizziness, nausea within 1-2 minutes.

DEATH WITHIN

10-15 MINUTES

12800 PPM

DEATH WITHIN 1 TO 3 MINUTES

Warning: Ensure that the meter is powered, at room temperature,

and in an area free of Carbon Monoxide (CO) before starting
measurements. If not, the meter will read incorrectly when
subsequently measuring CO.

Regulatory exposure limits for Carbon Dioxide (CO2)

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

OSHA: 5000ppm: Time weighted average over five 8-hour
workday should not exceed 5000ppm.

Building bulletin 101 (BB101): 1500ppm. UK standards for schools
state that CO2 averaged over the whole day (i.e. 9:00am to 3:30
pm) should not exceed 1500ppm.

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

EPA Taiwan (Type 1): Indoor areas such as department stores,
theaters, restaurants, libraries have acceptable CO2 concentration of
1000ppm over an 8-hour average period.

EPA Taiwan (Type 2): Indoor areas with special requirements for
good air quality such as schools, hospitals, and day care centers
have suggested CO2 level of 600ppm

Description

METER

1. Temperature and Humidity sensor

2. Primary display

3. Secondary display

4. Power and Set button

5. Start and Escape button

6. Mode and Recall button

7. Min-Max-Avg and Enter button

8. Memory and Down button

9. CO and CO2 sensors (on rear of meter)

10. Hold and Up button

11. AC Adaptor and Micro USB ports
Battery compartment on rear of meter

LCD DISPLAY

CO2 Carbon dioxide
CO Carbon monoxide
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
TA Air temperature
WBT Wet bulb temperature
%RH Relative humidity
C or F Celsius/Fahrenheit
CAL Calibration Mode
REC Manual/automatic data logging
RECALL View manually logged data

Low battery indicator

KEYPAD

Turns on and off the meter.

Enters setup mode while meter is off.
Sets as non-sleep mode with .

Exits setup/recall page.

Start automatic logging.

Press to switch displayed mode.

Long press to enter memory recall mode.

Freezes the current readings.

Selects unit or increases value in setup.
Cancels data hold function.

Press to manually record the reading.

Selects unit or decreases value in setup.

Activates MIN, MAX, TWA, STEL function. Saves and finishes

settings.

Battery Installation

1. Four (4) ‘AA’ batteries or an AC/DC adaptor powers the meter.

2. Install the batteries into the rear battery compartment observing
correct polarity.

3. When the adaptor is used, the batteries are disconnected

from the meter circuitry. The adaptor cannot be used to
charge rechargeable batteries.

4. When battery voltage is low, the battery symbol ( )
appears. Replace the batteries promptly.

Never dispose of used batteries or rechargeable batteries in household waste.
As consumers, users are legally required to take used batteries to appropriate collection sites, the retail store

where the batteries were purchased, or wherever batteries are sold.
Disposal: Do not dispose of this instrument in household waste. The user is obligated to take end-of-life devices
to a designated collection point for the disposal of electrical and electronic equipment.

Operation

Powering the Meter

Short press the /SET button to turn the meter ON or OFF. At
power up, the meter emits a short beep and performs a 30-second
warmup before entering normal operating mode. After the
countdown, the primary LCD will display the current readings. The
secondary display will alternate between the current date and time.

Taking Measurements

The meter begins measuring in the selected mode, when powered on,
and the sensor responds every 1 second. If the operating environment
changes (example: from high to low temperature), it requires 30
seconds for the CO2 sensor to respond and up to 30 minutes for the
relative humidity sensor to respond.

Measuring Carbon Dioxide (CO2)

4. Short press the M/REL button to change the mode to CO2 if

necessary.

5. To take a measurement, trace the GSM450 around the area of the

suspected leak.

6. The meter indicates the presence of carbon dioxide (CO2) in ppm

in the primary display. The secondary display indicates the current
date and time alternately.

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

Measuring Carbon Monoxide (CO)

1. Short press the M/REL button to change the mode to CO, if

necessary.

2. To take a measurement, trace the GSM450 around the area of the

suspected leak.

3. The meter indicates the presence of carbon monoxide (CO) in

ppm in the primary display. The secondary display indicates the
current date and time alternately.

4. The display will flash and an audible beeper sounds at 25 ppm

alerting the user to dangerous CO levels. The higher the
concentration of CO, the faster the beeper will sound. The
display will stop flashing once the measured CO is below the
alarm limit value.

Measuring Air Temperature and Calculating Dew point and
Wet bulb

1. Short press the M/REL button to change the mode to

air, dew point, or wet bulb temperature.

2. To take a measurement, trace the GSM450 in the testing area.

3. The primary display indicates the air temperature, dew point, or

wet bulb temperature depending on the selected mode. The
secondary display indicates the current date and time alternately.

4. Note that Dew Point and Wet Bulb Temperature displays are

calculations made from Air Temperature and Relative
Humidity measurements.

Measuring Relative Humidity %

1. Short press the M/REL button, if necessary, to change the mode to

Relative Humidity.

2. To take a measurement, place the GSM450 in the testing area.

3. The primary display indicates the relative humidity measurement

and the secondary display indicates the current date and time
alternately.

Advanced Functions

Data Hold

Short press the H/ button to freeze the readings on the display. The

"HOLD” icon flashes in the top left of the display. Short press the H/ button
again to unfreeze the readings on the display.

Note: the HOLD function is not operational in Min/Max/Avg mode.

Display Backlight

The meter is equipped with a backlight for easy viewing in dimly
lit areas. The backlight will activate for 10 seconds by pressing any
button.

MIN, MAX, STEL, TWA Recording

In normal operating mode, short press the MXMN/AV/ button to
view the minimum, maximum, weighted average, and current
readings. With each short press of the MXMN/AV/ button, the meter
displays the MIN, MAX, STEL, TWA, or current value along with elapsed
timer, in sequence. Short press the /ESC button to return to normal
operating mode.

In MIN and MAX modes, the meter shows the lowest (minimum) or
highest (maximum) reading in the primary display.

In STEL and TWA modes, the main display shows the weighted
average of readings for the past 15 minutes (STEL) or 8 hours (TWA).
TWA and STEL mode are only operational in CO2 mode.

In CURRENT mode, the primary display shows the current readings. The
secondary display shows the elapsed timer. Press the /ESC button to
exit and return to normal operating mode.

NOTES:

1. If the meter is ON for < 15 minutes, the STEL value will be

the weighted average of readings taken since power on.
Similarly, for the TWA mode when the meter has been ON
for < 8 hours, the display only shows a weighted average of
the readings up to the moment.

2. The GSM450 requires at least 5 minutes calculating STEL and

TWA. The display shows “----” during the first 5 minutes from
power ON.

3. While in HOLD mode, the STEL and TWA values will continue to

update every 5 minutes.

4. Hold, Record, and Recall functions are not operational while in

Min/Max/Avg mode.

5. TWA and STEL will function only in CO2 mode

6. The unit of measure can be changed while in Min/Max mode.

Manual Data Recording

The GSM450 has 99 memory locations for which to store readings one
at a time.

1. While in normal operating mode or hold mode, short press the

MEM/ button to store a reading. The REC icon flashes on the
display for approximately 3 seconds. The primary display briefly
shows the memory location.

2. Each measurement parameter is saved, not just the currently

displayed parameter. (For example, when recording CO
readings, the CO2, %RH, and air temperature will also be
recorded).

3. Short press the H/ button to freeze the readings on the

display before recording the data if the readings change too
quickly.

Note: The manual recording mode is not operational in Min/Max
mode.

Recalling Manually Stored Readings

The meter can recall up to 99 previously saved readings.

1. While in normal operating mode, long press the M/RCL

Automatic Datalogging

button until ‘Recall’ flashes on the display.

2. Short press the H/ or MEM/ buttons to scroll through

the memory locations. The selected memory location will
flash for approximately 3 seconds and then the stored
reading will display on the screen.

3. Short press the M/RCL button to change the displayed

measurement parameter.

4. The secondary display shows the time and date the data was

recorded into memory.

5. To exit memory recall mode, short press the /ESC button.

The GSM450 automatically records CO2, CO, Temperature, or RH
readings and can store up to 32,000 records. The sample rate can be set

from 1 second to 4 hours 59 minutes and 59 seconds. See ‘Setup Mode’

for information on setting the sample rate.

1. After the sample rate is selected, long press the /ESC button

to begin logging. The ‘rec’ icon flashes and the primary display
shows the real time value. The secondary display shows the
current time and date alternately.

2. Short press the M/RCL button to select a different measurement

mode to record.

3. To exit the datalogger mode, long press the /ESC button. The

‘rec’ icon stops flashing.
Notes:
Previous records are overwritten any time logging is started.
The M/RCL button is the only button that is operational while in
datalogging mode.

CO Alarm

The meter features an audible alarm (80db beep) that warns when
CO concentration exceeds the set limit. The beeper stops when the
readings fall below the limit. The meter beeps again if the value

exceeds the limit. See the section ‘Setup Mode’ for more

information.

Auto Power OFF

The meter turns off automatically after 20 minutes of inactivity. To
override the function, long press both the /SET and H/ buttons

while powering ON the meter until “n” appears in the display.

NOTE: Auto power off is not operational while in calibration mode.

Setup Mode

While the meter is OFF, long press the /SET button to enter the setup
mode.
To exit the setup mode, short press the /ESC button at any time
during setup.

P10 Clearing the Manual Recording Memory

Clearing the memory will erase ALL the manually stored records.

1. Upon entering setup mode, P10 and “CLr” display on the LCD.

2. Short press the MXMN/AV/ button to advance to P11 and

make a selection.

3. Short press the H/ or MEM/ button to select YES or

NO. ‘YES’ will erase all the manually stored records.

4. Short press the MXMN/AV/ button to save the selection and

return to P10.

5. Short press the /ESC button to exit without saving.

6. Short press the H/ button to advance to the next step.

P20 Setting the CO Alarm

1. When in alarm setup mode, P20 and “ALAr” are displayed.

Short press the H/ button to advance to P20 if necessary.

2. Short press the MXMN/AV/ button to advance to P21 and set

the CO alarm threshold. The current set value will blink on the

display.

3. Short press the H/ button to increase or the MEM/ button

to decrease the value. The alarm range is from 15 to 200ppm

and each press of the buttons will advance 5ppm.

4. Short press the MXMN/AV/ button to save the selection and

return to P20.

5. Short press the /ESC button to exit without saving.

6. Short press the H/ button to advance to the next step.

P30 Changing the Temperature Units

1. When in temperature setup mode, P30 and “unit” display

on the LCD. Short press the H/ button to advance to P30

if necessary.

2. Short press the MXMN/AV/ button to advance to P31 and

change the temperature units. The current temperature

unit displays on the LCD.

3. Short press the H/ or MEM/ button to toggle between °C

and °F.

4. Short press the MXMN/AV/ button to save the setting and

return to P30.

5. Short press the /ESC button to exit without saving.

6. Short press the H/ button to advance to the next step.

P40 Setting the Datalogging Sampling Rate

1. When in datalogging setup mode, P40 and “rAtE” display

on the LCD. Short press the H/ button to advance to P40

if necessary.

2. Short press the MXMN/AV/ button to advance to set the

sampling rate for datalogging. The hour digit will blink in the

secondary display.

3. Short press the H/ button to increase the time or short

press the MEM/ button to decrease the time.

4. Short press the MXMN/AV/ button to save the setting

and advance to the minute setup.

5. Short press the H/ button to increase the time or short

press the MEM/ button to decrease the time.

6. Short press the button to save the setting and

advance to the second setup.

7. Short press the M button to save the settings and
return to P40.

8. Short press the button to exit without saving.

9. Short press the button to advance to the next step.

Note: The datalogging sampling range is from 1 second to 4 hours 59
minutes 59 seconds.

P50 Changing the Barometric Pressure Compensation

1. When in pressure setup mode, P50 and “PrES” display on the

LCD. Short press the H/ button to advance to P50 if

necessary.

2. Short press the MXMN/AV/ button to set the pressure

compensation value for the CO2 measurement. The current

pressure compensation value in hPa will flash on the LCD.

3. Short press the H/ or MEM/ button to adjust the

barometric pressure value. The pressure compensation

range is from 70 to 199 hPA.

4. Short press the MXMN/AV/ button to save the setting and

return to P50.

5. Short press the /ESC button to exit without saving.

6. Short press the H/ button to advance to the next step.

P60 Setting the Real-Time Clock

1. When in Real-Time Clock mode, P60 and “rtC” display on the

LCD. Short press the H/ button to advance to P60 if

necessary.

2. Short press the MXMN/AV/ button to advance to P61 and

set the time as 12-hour or 24-hour format. The current time

format will flash on the LCD.

3. Short press the H/ or MEM/ button to change the format

between 12-hour and 24-hour.

4. Short press the MXMN/AV/ button to save the setting and

advance.

5. The year will flash in the secondary display. Short press the

H/ or MEM/ button to change the value.

6. Short press the MXMN/AV/ button to save the setting

and advance to the month setup.

7. Short press the H/ or MEM/ button to change the value.

8. Short press the MXMN/AV/ button to save the setting and

advance to the next step.

9. Repeat the above steps to complete the setup for the

month/day/hour/minute/second settings.

10. Short press the MXMN/AV/ button to save the selection and

return to P60.

11. Short press the /ESC button to exit setup mode.

Calibration

RH CALIBRATION

The meter is calibrated to a standard 33% and 75% salt solution
bottle. Calibration must be performed in a controlled
temperature environment of 25°C.

CAUTION: Do not calibrate the humidity without the default calibration
salts. The meter will lose its current calibration data and will become
inoperable.

33% Calibration

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

2. Long press the /ESC, MEM/ and /SET buttons

simultaneously to enter calibration mode.

3. In calibration mode, “CAL” and the current value (32.8% if at

25°C) will blink on the LCD.

4. The meter is now calibrating, and will finish in about 60

minutes, when the current value stops blinking. “CAL” will

continue to blink on the display.

5. To abort the calibration, power the meter OFF at any time.

75% calibration

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

5. To abort the calibration, power OFF the meter at any time.

PC Interface

bottle.

2. Long press the MXMN/AV/ button to enter 75% calibration.

3. “CAL” and current value (75.3% if at 25°C) will blink on the LCD.

4. The meter is now calibrating. The calibration is complete in

about 60 minutes. The values will stop flashing and the meter

powers OFF automatically when calibration is complete.

This meter has the capability to connect to and communicate with a
PC. To install and use the software, please refer to the instructions
provided on the supplied CD-ROM and/or the instructions provided
in the HELP Utility within the software program. Software can be
downloaded here:

Download Triplett Product Software — Triplett — Triplett
Test Equipment & Tools

Error

Problem

Solution

Ensure that batteries are
properly

installed with correct
polarity

Display

No display when pressing
power button

Press and hold power
button to retry

Replace batteries

Open the battery
compartment and

using a small metal tip,
press the

reset button

Display

Readings frozen on display

Check to see if data hold
function is

activated. Press hold to
deactivate.

Display

Slow Response

Check for air flow
blockage to

sensors

E01/E33

CO2 sensor is not working

Replace the battery

E02

Measurement is below the
range of the meter

Check readings in a
different area

E03

Measurement is above the
range of the meter

Check readings in a
different area

E04

Data error

Contact Extech for
service

E11

Humidity calibration Error

Retry humidity
calibration

E16

CO calibration error

Contact Extech for
service

Troubleshooting

E31

A/D or temperature sensor
failure

Contact Extech for
service

E32

Memory failure

Contact Extech for
service

E33

A/D or humidity sensor failure

Contact Extech for
service

E33

Measurement circuit failure

Contact Extech for
service

Maintenance

CLEANING AND STORAGE

1. Clean the meter 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 temperature
ranges in the specifications section).

Specifications

Function

Range

Resolution

Accuracy

0 to 5000ppm

1 ppm

±(5%rdg + 30ppm)

CO2

5001 to
9999ppm

1 ppm

Not specified

Pressure dependence: +1.6% of reading per kPa
deviation from

normal pressure (100kPa)

<100 ppm

1 ppm

±(10ppm)

CO

101 to 500 ppm

1 ppm

±(10%rdg)

501 to 1000 ppm

1 ppm

±(20%rdg)

Temperature

-20 to 60°C

0.1°

±0.6°C

-5 to 140°F

0.1°

±0.9°F

Humidity

0.1 to 99.9%

0.1%RH

±3%(10 to 90%) @25°C

±5%(all other
ranges)@25°C

Wet Bulb

-5 to 59.9°C

0.1°

23 to 140°F

Calculated from RH and

Dew Point

-20 to 59.9°C

0.1°

Temperature

-4 to 140°F

Display

LCD with backlight

Display size

26 x 44 mm (1.0 x

1.7”)

Warm-up
period

30
seconds

Response
Time CO2: <30 seconds (90% step change)

CO: <60 seconds (90% step change)

Tair: <2 minutes (90% step change)

RH: <10 minutes (90% step change)

Sensor Type

CO2: NDIR (non-dispersive infrared) technology

Humidity: Capacitance sensor

Temperature (air): Thermistor

Operating Conditions

-20 to 50oC (-4 to 122oF) CO2 sensor

0 to 50oC (32 to 122oF) CO sensor

-20 to 50oC all other parameters

Storage Conditions

-20 to 60oC (-4 to 140oF); 10 to 90% RH non­condensing

Power Supply

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

Battery Life

approx. 24 hours (alkaline batteries)

Dimensions / Weight

205 x 70 x 56mm (8.1 x 2.8 x 2.2“) / 200g (7.1

oz.)

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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