General Specifications; Applying The Specifications; Introduction; How The Super-Thermometer Measures - Fluke 1594A Technical Manual

2.2.4

General Specifications

Table 8 General Specifications

Warm-up period
Measurement range
Measurement current range
Measurement current reversal interval:
Sample period of 1 second or 2 seconds
Sample period of 5 second or 10 seconds
Standby current range
AC power
Fuse Rating
Specified operating temperature
Absolute operating temperature
Storage temperature
Operating relative humidity, 5°C to 30°C
Operating relative humidity, 30°C to 40°C
Storage relative humidity
Maximum operating altitude
Dimensions:
Height
Width
Depth (with handles)
Depth (without handles)
Weight
2.2.5

Applying the Specifications

2.2.5.1

Introduction

The purpose of this section is to help the user apply the specifications in measurement scenarios for which
the Super-Thermometer was designed. The following uncertainty calculation examples may not include all
uncertainties that are present in a measurement. Be sure to follow current best practices in uncertainty analysis
to correctly calculate measurement uncertainty.
2.2.5.2

How the Super-Thermometer Measures

In order to understand how to apply the specifications, it is important to know how the Super-Thermometer
measures. The fundamental measurement of the Super-Thermometer is the resistance ratio. It is the ratio
between an unknown resistance (R
measurement is needed, the ratio is multiplied by the value of the reference resistor to calculate the resistance
of the R resistor (for more information refer to Measurement Timing in the Menus and Screens section).
x
If a temperature reading is required, the R
bration coefficients entered into the Probe Library. When ITS-90 is selected as the temperature conversion, the
R resistance is divided by the RTPW (resistance at the triple-point of water) value that is entered in the probe
x
definition. The resulting value is called W
then applied to W
Since W is a ratio between a probe's resistance at temperature (R
T90
curacy relies primarily on ratio accuracy if both R
Also, this only applies if the RTPW was measured by the Super-Thermometer and entered into the probe
definition.
) and a reference resistor (R
x
resistance value is used to calculate the temperature using the cali-
x
T90
to calculate the temperature reading of the probe.
T90
30 minutes
0 W to 500 kW
0.001 mA to 20 mA
0.2 second
1.2 second
0.001 mA to 2 mA
100 V to 230 V (± 10 %)
50 or 60 Hz
2 A – T – 250 V
15 °C to 30 °C
5 °C to 40 °C
0 °C to 40 °C
10 % to 70 %
10 % to 50 %
0 % to 95 %, non-condensing
3000 m
147 mm (5.8 in)
439 mm (17.3 in)
447 mm (17.6 in)
406 mm (16.0 in)
7.3 kg (16.0 lb)
) – either internal or external. If a resistance
s
. The probe calibration coefficients and the ITS-90 equations are
) and its RTPW, W
T90
(R ) and RTPW are measured in close proximity in time.
T90 x
Introduction and Specifications
Specifications
measurement ac-
T90
9