General Tools and Instruments DT4947SD - Manual (Page 3)

INTRODUCTION
Thank you for purchasing General Tools & Instruments’ DT4947SD 4-Channel Thermometer
with Datalogging SD Card. Please read this user’s manual carefully and thoroughly before
using the instrument.
The DT4947SD is a general-purpose handheld instrument that can measure up to four
channels of temperature with 0.4% accuracy using either of two kinds of optional
accessories: thermocouples or Pt 100 ohm probes (resistance-temperature detectors, or
RTDs). RTDs are slowly replacing thermocouples in many industrial applications below
1100ºF (600ºC) due to their superior accuracy and repeatability. When used as inputs to the
DT4947SD, Pt 100 ohm probes can measure and display temperatures from -328º to
1562ºF (-200º to 850ºC).
Although thermocouples are not as accurate as other types of thermometers, they more
than make up for this shortcoming with an extended measurement range. For example,
the DT4947SD can measure and read out temperatures from -148º to 2372ºF
(-100º to 1300ºC) using Type K thermocouples, and temperatures from -148º to 2192ºF
(-100º to 1200ºC) using Type J thermocouples. Type R and Type S thermocouples have an
even higher upper limit. These very wide ranges, plus a fast response time and a low price
tag, suit thermocouple thermometers for a variety of commercial and industrial tasks
requiring measurement of very high and low temperatures. Examples include applications
in the food and chemical processing industries, HVAC (heating, ventilation and air-
conditioning), power generation and paper production.
Because it is microprocessor-based, the DT4947SD can make full use of the portability,
reliability and large storage capacities that SD memory cards offer. Measurements can be
made automatically at any sampling rate between one second and one hour. After time-
stamping and storing the measurements on an SD card plugged into the instrument (a
process called datalogging), the user can remove the card and plug it into to a laptop or
desktop computer either directly or through an SD card reader. The data logs are stored on
the card as files with the .xls extension, which can be opened by Microsoft’s Excel
application.
The DT4947SD has a backlit 2-1/2 in. diagonal display and is powered by six “AA” Alkaline
batteries or an optional 9-VDC AC adapter.
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