General Tools General Tools HT20 Manual

USB

RH/TEMPERATURE/GPP

DATA LOGGER with

LCD DISPLAY

USER’S MANUAL

HT20

99 Washington Street
Melrose, MA 02176

Phone [phone]
Toll Free 1-800-517-8431

Visit us at www.TestEquipmentDepot.com

Please read this manual carefully and thoroughly before using this product.

TABLE OF CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 –4

Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 –5

Safety Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

What’s in the Blister Pack. . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Product Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 –7

Setup Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 – 13

Installing/Replacing the Battery . . . . . . . . . . . . . . 7 –8

Install Software and Drivers. . . . . . . . . . . . . . . . . 8 –9

Configure the Unit . . . . . . . . . . . . . . . . . . . . . . 10 – 13

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . 13 – 17

Deploy the Unit . . . . . . . . . . . . . . . . . . . . . . . . 13 – 14

Stop Logging and Import Logs . . . . . . . . . . . . . 14 – 15

Viewing, Printing and Exporting Data Logs . . . . 15 – 16

Other Indications . . . . . . . . . . . . . . . . . . . . . . . 16 – 17

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Maintenance Tips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Return for Repair Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2

INTRODUCTION

Thank you for purchasing General Tools & Instruments’
HT20 USB RH/Temperature/GPP Data Logger with LCD
Display. Please read this user’s manual carefully and
thoroughly before using the instrument.

The HT20 is a low-cost, compact, battery-powered thermo­hygrometer capable of unattended logging (recording) of the
ambient temperature and relative humidity (RH) of an
environment for days, weeks or months. In addition, software
included with the product can also calculate and display
absolute humidity levels in units of grains per pound (GPP) or
g/kg. Also called mixing ratio, GPP is a more useful moisture
metric than RH to water damage remediators. Using RH
alone, a remediator might unknowingly introduce moist air—
with a low RH but a high GPP—during a job’s drying phase.

Data logging can be started or stopped by pushing a button
on the unit, eliminating the need to bring a laptop to the job
site. After a data log has been captured and stored, it can be
uploaded as a .txt file to any PC running the Windows
Windows

®

XP operating system after plugging the HT20 into
one of the computer’s USB ports. The HT20’s internal flash
memory is large enough to store 16,300 pairs of RH and
temperature readings.

Included with the product—which is slightly larger than a
thumb drive—is a mini-disc with the drivers needed to
interface the unit to the computer, as well as software that
can display a data log file as a table or graph and/or export it
to Microsoft Excel. Exporting to Excel is recommended for
sophisticated trending and analysis of humidity and
temperature data and easy detection of unexpected
excursions.

Windows®7 and Windows®XP are registered trademarks of Microsoft Corporation.

®

7 or

3

Applications for the HT20 include:

• Water damage remediation—Because the HT20 is
designed to be deployed and left in place over the
duration of the job, it is always in equilibrium with the
environment.

• Process control—The HT20 enables, simplifies and cuts
the cost of environmental monitoring of office buildings,
greenhouses, food and equipment storage facilities,
wineries, freezers, shipping containers, HVAC/R
installations, computer rooms, labs, libraries, museums
and saunas.

• Electronics manufacturing—Alerts provided by the low­humidity alarm function of the HT20 can mitigate the risk
of damaging high-voltage static discharges.

KEY FEATURES

• One button starts/stops data logging without a PC

• Plug-and-play USB 2.0 interface; no need for cables,
cradles or docks

• Large storage capacity: 16,300 pairs of RH and
temperature readings

• 3-1/2-digit LCD displays real-time temperature and
humidity readings; also indicates device working status
and “memory full”

• Included software is used to set: Sampling time from
10 seconds to 12 hours; Hi/Lo alarm setpoints for
humidity and temperature; Temperature unit (°F or °C)

4

• Software also calculates and plots GPP and dew point and
wet bulb temperatures and displays data logs as time­based graphs synchronized to your PC’s clock

• One-click exporting of logs to Excel or Word

• Long battery life (up to one year)

• Includes USB extension cable

• One-year warranty

SAFETY INSTRUCTION

Do not use the HT20 in the presence of flammable or
explosive gases.

WHAT’S IN THE BLISTER PACK

The HT20 comes in a blister pack that also contains

•

One “1/2 AA” battery. Replacement batteries
(Part No. BA10) are available from General.

• A disc with software drivers for Windows7 and Windows
XP computers, the ELusb V1.21.3 program for capturing
data logs and displaying them as curves, and a PDF of
this user’s manual

• A USB extension cable

• A hard copy of this user’s manual (inside the fold-over
card)

5

PRODUCT OVERVIEW

Fig. 1a below shows the main components, controls and
connectors of the HT20. Fig. 1b (on the facing page) shows
all possible indications on the HT20’s display. Familiarize
yourself with their names and functions before moving on to
the Setup Instructions.

E

F

D

,

Fig. 1a. The components, controls and connector

C

B

of the HT20

A. Temperature and humidity sensor window
B. Battery compartment (latch is on rear of unit)
C. 3-1/2-digit LCD (displays temperature and humidity

readings; also indicates device working status and

“memory full”)
D. USB plug
E. Protective cap
F. MODE button

6

A