5
Introduction and Specications
Specications
2 Introduction and Specications

2.1 Introduction

The Fluke family of Hart Super-Thermometers long ago established the standard for easy-to-use, precision
temperature measurement instrumentation. Laboratories worldwide have selected the Super-Thermometer
not only for the assurance of achieving high-quality results, but also for the innovative features that increase
productivity in the lab. The Fluke 1594A and 1595A Hart Super-Thermometers continue this legacy adding
new patent pending measurement technology and features that truly are best in class. Below is a summary of
key capabilities and features.
Typical 1595A accuracy 0.2 ppm (0.05 mK), 1594A accuracy 0.8 ppm (0.2 mK)
Sample rates as fast as 1 second
Measures SPRTs, HTPRTs, PRTs, and thermistors
Four input channels on the front panel accept most probe terminations with the patented DWF, gold-
plated, tellurium-copper, quick-connect terminals
Congurable standby current for each input channel minimizes self-heating transients when scanning
between channels
Two input channels on the back panel, dedicated for external standard resistors, keep the front panel
inputs free for Reference Thermometers or Standard Resistors and UUTs
Channel Select Keys above each input channel change color to indicate whether a channel is actively
measuring, in standby, or inactive—pressing a channel key activates the selected channel
Temperature-controlled internal reference resistors allow for traceable temperature and absolute
resistance measurements in ambient conditions from 15 °C to 30 °C
Patent pending, Ratio Self-Calibration performs a linearity check or calibration of the Super-
Thermometer ratio accuracy without the need of any external equipment
Automated Zero-Power Measurement allows for determination and/or cancellation of a thermometer’s
self-heating error
Updated computer interface with USB control, RS-232, and IEEE-488 included as standard
Ethernet connection allows for remote view of the Super-Thermometer’s display from a web browser
USB memory device on the front panel to accommodate data logging, transfer of probe parameters, and
storage and retrieval of Super-Thermometer user congurations
VGA output allows the Super-Thermometer’s screen to be displayed on a VGA monitor
Selectable operating language: English, Chinese, Japanese, Spanish, French, German, or Russian
Intuitive User Interface makes the Super-Thermometer easy to congure and use right out of the box

2.2 Specications

2.2.1 General
Current best practices in metrology require uncertainty analyses to be in compliance with the ISO Guide to the
Expression of Uncertainty in Measurement (often referred to as the “GUM”). For convenience, the specica-
tions in this section are listed in k = 2 (95%) coverage and in k = 3 (99%) coverage to allow the user to easily
apply the specications in an uncertainty analysis.
The following specications apply after the standard warm-up period of 30 minutes. The Super-Thermometer
is designed to measure with accuracy and stability without the need for internal auto-cal or zeroing routines.
To realize the full potential of measurement ability, accepted metrology practices such as the use of proper
wiring should be adhered to. In addition, it is important to ensure that the instrument is correctly set up.
The specications are divided into three categories: primary specications, ancillary specications, and gen-
eral specications.