Global Specialties GNV-725 User manual

TIME

REC

HOLD

C

F

T1

K-TYPE

T2

POWER-UP OPTIONS

SETUP

CLOCK

INTV

C

F

0

TEMP: 20 C

HUMIDITY:

(

328

200

4

)

F

60 C

2498

1370

%RH

140

F

100

F

C

REC

GNV-720
GNV-725

Humidity Temperature Meters

User Manual

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Table Contents

Safety.............................................................................................................2

Compliance and Certications....................................................................2-3

Introduction....................................................................................................3

Specications ................................................................................................4

Instrument and Display Description...............................................................5

Operating Instructions.................................................................................6-7

Software Installation.......................................................................................7

Using the Software.........................................................................................8

Calibration Instructions..............................................................................9-10

Warranty/Service Information.......................................................................11

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Unauthorized duplication of Global Specialties documentation materials
is strictly prohibited. Customers are permitted to duplicate and distribute
Global Specialties documentation for internal educational purposes only.

Safety

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Safety

To avoid personal injury and/or product damage, review and comply with
the following safety precautions. These precautions apply to both operating
and maintenance personnel and must be followed during all phases of
operation, service, and repair of this meter.

Dry Conditions

Hands, shoes, oor, and work bench must be dry. Avoid making
measurements with dampness, or other environmental conditions that might
affect safety.

Cleaning

Use a soft cotton cloth lightly moistened with a mild solution of detergent
and water. Do not allow any portion to be submerged at any time. Dry
thoroughly before attempting to make measurements. Do not use solvents
or expose to solvent fumes as they may cause deterioration or damage.

Do not operate:

• In the presence of noxious, corrosive, flammable fumes, gases,

vapors, chemicals, or finely-divided particulates.

• In environments where there is a danger of any liquid being spilled

on the meter.

• In air temperatures exceeding the specified operating temperatures.

• In atmospheric pressures outside the specified altitude limits or

where the surrounding gas is not air.

Compliance and Certications

CE Compliance

This product meets the essential requirements of the applicable European
Directives as follows:

• 89/336: Electromagnetic Directive (EMC)

• 2011/65/EU: Restriction of Hazardous Substances Directive (RoHS)

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Disposal

(Applicable in the European Union and other European
countries with separate collection systems). This product is
subject to Directive 2012/19/EU of the European Parliament
and the Council of the European Union on waste electrical and
electronic equipment (WEEE), and in jurisdictions adopting that
Directive, is marked as being put on the market after August
13, 2005, and should not be disposed of as unsorted municipal
waste. Please utilize your local WEEE collection facilities in the
disposition of this product.

Caution! Refer to the operating instructions.

Introduction

The GNV-720 and GNV-725 are digital humidty, temperature meters that
measure relative humidity and ambient temperature as well as employing a
“K” type thermocouple for more precise contact temperature measurements.
The GNV-725 expands the capabilities with data logging functionality.

Kit Includes

This meter comes with the following:

• Instruction manual

• PC software (only with GNV-725)

• RS-232 cable (SE-300, only with GNV-725)

• 9 V battery

• Carrying case

• Probe holder

• K type bead thermocouple (CT3240*)

*The CT3240 is rated for - 50˚C to 200 ˚C. For higher temperature
measurements please order the CT3241.

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Specications

Humidity 0% to 100%

Temperature @ T1 -20 ˚C to +60 ˚C (-4 ˚F to +140 ˚F)

Temperature @ T2 -200 ˚C to +1370 ˚C ( -328 ˚F to +2498 ˚F)

Humidity 0.1 % RH

Temperature @ T1 0.1 ˚C (0.1 ˚F)

Temperature @ T2

(CT3240*)

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Specications

Measurement Range

Resolution

-200 ˚C to +200˚C, 0.1 ˚C
200 ˚C to 1370 ˚C, 1 ˚C

(-200 ˚F to +200 ˚F, 1 ˚F)

(200 ˚F to 2498 ˚F, 1 ˚F)

Accuracy

Humidity ± 2.5 % RH at 25 ˚C

Temperature @ T1 ± 0.7 ˚C (± 1.4 ˚F)*

Temperature @ T2 ± 0.5 % reading + 1 ˚C (± 0.5 % reading + 2 ˚F)

Response Time

Humidity 75 s

Temperature 40 s

Signal Output RS-232 data output

Display 4 digit LCD

Weight 320 g

Dimensions

Meter 186 x 64 x 30 mm

Probe 190 x 15(D) mm

Environmental

Battery Life Approx. 100 hrs w/ alkaline battery (9V)

Operating Environment 0 ˚C to 50 ˚C (32 ˚F to 122 ˚F)

Total Memory (GNV-725) 16,300 data points

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Instrument and Display Description

1

2

T1

GNV-720

TEMPERATURE METER

5

6

7

REL

C

TEMP: 20

4 F

)(

200

HUMIDITY:

POWER-UP OPTIONS

C

0

3

( )

K-TYPE

T2

HUMIDITY

4

8

HOLD

9

F

60

C

F140

1370

C

C
F

2498

F328

100

%RH

11

LAC

232-SR

V9CD

9V BATTERY

NEDA 1604 6F22 00

PLEASE READ

MANUAL FOR SAFE

OPEN

1. Dust mask

2. Sensor probe

3. T2 channel, “K” type thermocouple

4. LCD display

5. Power button

6. ∆REL (GNV-720)
TIME (GNV-725)

7. ˚C control (GNV-720)
REC (GNV-725)

8. MAX/MIN button

9. HOLD button

10. ˚F control (GNV-720)

˚C/˚F (GNV-725)

˚C ˚F : Celsius and Fahrenheit
indicators

%RH : Relative humidity indicator

MAX : The maximum value is

displayed

MIN : The minimum value is
displayed

: Auto power off indicator

: Data hold function indicator

m-d : Month and day

h:m : Hour and minute

m:s : Minute and second

Y : Year

11. “K” type offset calibration screw

12. Digital output connector (RS-232)

13. AC power adapter connector

: Low battery indicator

K : Thermocouple type indicator

∆REL : Relative mode indicator

14. Tripod mounting hole

15. Battery cover

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Operating Instructions

• Press the power button to turn the Humidty Temperature Meter ON or

OFF. Upon power up, the available memory will be displayed (GNV-

725).

• To measure the ambient temperature and humidity place the meter

within the desired environment and press the power button.

• To measure with the “K” type thermocouple, first insert the plug portion

into the channel labeled “T2” at the top of the meter. Then position the
bead on the object under test and press the power button.

• To switch the temperature scale, press either the ˚C or ˚F button.

• To hold the current reading, press the HOLD button. To release this

value, press the HOLD button again.

• To view the maximum or minimum values, press the MAX MIN button.

The maximum value is displayed while MAX is showing and the
minimum value is displayed while MIN is showing. The maximum and
minimum values will both be displayed while MAX and MIN are both
blinking. To exit this mode, simply hold the MAX MIN button for two
seconds.

• To view the change in values press the ∆REL button. This uses the

current value as reference then takes the difference with all subsequent
values and then displays it.

• The auto power off function is the default setting and turns the meter

off after 30 minutes in the absence of button presses or RS-232
communication. This can be disabled by pressing and holding rst the
HOLD button and then the power button together until you hear two
beeps. The  will no longer be displayed indicating the meter will not

turn off automatically anymore.

• Replace the battery once the symbol is displayed.

• The digital output is a 9600 bps N 81 serial interface.

Data Logging

• To initiate data logging press the REC button. Pressing the REC button

again will stop recording. To clear the memory, rst power the meter off.
Then, while holding the REC button, press the power button. Release
both buttons and “CLR” will be displayed to show that the memory has

be cleared.

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• To set up the clock, press and hold the MAX MIN button, then power

on the meter. Press the TIME button. Then press the REC or ˚C/˚F
buttons to increase or decrease the value. Press TIME again to adjust
the next item in the following order: year, month, day, hour, minute.
Press TIME one more time to save settings. Pressing the power button
at any time will cancel the process.

• To set the recording interval press and hold the MAX MIN button then

power on the meter. Press the HOLD button. Then press the REC or
˚C/˚F buttons to increase or decrease the value. Press HOLD again

to adjust the next item. Press HOLD one more time to save settings.
Pressing the Power button at any time will cancel the process.

• To display the time press the TIME button. The time will be displayed

with the year at the top, the month and day at the bottom left, and the
hour and minute on the bottom right of the LCD. Press TIME again
to exit this mode. This will not interfere with recording, maximum, or
minimum holding values.

Warning! Do not touch or manipulate sensor.

Do not expose the sensor to direct light, this can cause false
readings.

Do not expose the sensor to static electricity.

Software Installation

System requirements:

• Software download

• RS-232 cable (SE-300)

• Windows 10

• 16 MB RAM and 5 MB hard disk space

Installation:

• Close all other applications.

• Open TestLink file (SETUP.exe). The installer should start

automatically.

• The default save location should be c:\program files\TestLink.

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Using the Software

• Run the TestLink software by clicking the TestLink file.

Sample Rate

Meter Control
Panel

Real Time
Graph

Real Time
Table

• To take measurements, click on the run icon from the tool bar. The

graph and table should automatically start populating with data. The
interval can be changed by typing in the sample rate box.

• (GNV-725) Data logging can be selected by clicking the appropriate

menu at the top of the tool bar. Data will automatically be downloaded.
Once the data is loaded succesfully a new window will pop up.

Data Sets

Real Time
Graph

Real Time
Table

• The data sets window displays how many sets were loaded including

the details for each (start date, start time, recording rate, and data
length). Clicking on any of the sets will populate the graph and table
with the data.

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Calibration

Humidity

1. Turn the unit off. Pres and hold MAX MIN, HOLD and ˚C buttons. While these

buttons are pressed, turn the power on. Release the buttons and all the segments
on the LCD will blink.

2. Within three seconds, press the ˚F and ∆REL buttons at the same time to enter

the calibration mode.

3. In calibration mode, the humidity reading will blink and “CAL1” will appear on the
second display.

4. Insert the humidity probe into the standard humidity cavity of 32.8% RH at 25 ˚C.
Let the system stabalize for 20 minutes then press the MAX MIN button to create
the calibration data. If the value is out of tolerance, the meter will beep twice and
remain in “CAL1” mode. If the value is within tolerance the meter will go directly
into “CAL2” mode and display “CAL2” on the second display.

5. Insert the humidity probe into the standard humidity cavity of 75.3% RD at 25 ˚C
and let the system again stabalize for 20 minutes. Press the MAX MIN button
to create the calibration data. The meter will beep twice if the value is out of
tolerance. The meter will exit calibration mode if the value is within tolerance.

T1 Temperature

1. Turn the unit off. Pres and hold MAX MIN, HOLD and ˚C buttons. While these
buttons are pressed, turn the power on. Release the buttons and all the segments
on the LCD will blink.

2. Within three seconds, press the ˚F and HOLD buttons at the same time to enter
the calibration mode.

3. In calibration mode, the temperature reading will blink and “CAL1” will appear on
the second display.

4. Insert the probe into the standard chamber of 0 ˚C (32 ˚F). Let the system
stabalize for 20 minutes then press the MAX MIN button to create the calibration
data. If the value is out of tolerance, the meter will beep twice and remain in
“CAL1” mode. If the value is within tolerance the meter will go directly into “CAL2”
mode and display “CAL2” on the second display.

5. Insert the humidity probe into the standard chamber of 40 ˚C (104˚ F) and let the
system again stabalize for 20 minutes. Press the MAX MIN button to create the
calibration data. The meter will beep twice if the value is out of tolerance. The
meter will exit calibration mode if the value is within tolerance.

9

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Calibration Notes

• To exit calibration mode at any point during the calibration procedure, simply press

the power button. This will cancel the calibration and will not save any data.

• To reset factory conditions, press the and hold the power button and HOLD

buttons together.

• It is recommended to first insert the probe into the standards for 20 minutes before

initiating the calibration procedure to ensure the best results.

• During calibration, the temperature scale is fixed on the ˚F scale.

• During calibration, the auto power off function is disabled and will be enabled

again after exiting calibration mode.

10

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Limited One-Year Warranty

Global Specialties (a brand of Cal Test Electronics) warrants these products to be free
from defective material or workmanship for a period of 1 year from the date of original
purchase. Under this warranty, Global Specialties is limited to repairing the defective
device when returned to the factory, shipping charges prepaid, within the warranty

period.

Units returned to Global Specialties that have been subject to abuse, misuse, damage,
or accident, or have been connected, installed, or adjusted contrary to the instructions
furnished by Global Specialties, or that have been repaired by unauthorized persons,
will not be covered by this warranty.

Global Specialties reserves the right to discontinue models, change speci
price, or design of this device at any time without notice and without incurring any
obligation whatsoever.

The purchaser agrees to assume all liabilities for any damages and/or bodily
injury which may result from the use or misuse of this device by the purchaser, his
employees, or agents.

This warranty is in lieu of all other representations or warranties expressed or implied
and no agent or representative of Global Specialties is authorized to assume any
other obligation in connection with the sale and purchase of this device.

cations,

Service

If you have a need for calibration or repair services, technical, or sales support, please
contact us:

451001-000 Rev A

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