Service Manuals, User Guides, Schematic Diagrams or docs for : Keithley Appnotes 2765 Thermistors
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download 2765 Thermistors documenatation <<
Text preview - extract from the document
A G R E AT E R M E A S U R E O F C O N F I D E N C E tant, because contemporary data-acquisition
systems have built-in linearization correc-
tion features making hardware linearization
unnecessary.
Temperature Measurement
Methods
There are several techniques for meas-
uring temperature with a thermistor, the
most common being the two-wire and four-
wire techniques.
The two-wire technique works by forc-
ing current through the thermistor and
measuring the resulting voltage. The benefit
is that it's a simple method using only two
wires, making it easy to connect and imple-
ment. The main drawback is that the lead
resistance is part of the measurement, which
Basics of Temperature
can cause some error.
In the four-wire technique, a current is
forced through the thermistor and a voltage
Measurement:
is measured. However, the current is sourced
on one set of leads, while the voltage is
sensed on a different set of leads. The voltage
Thermistors is sensed at a different spot from the source
current. This means the test lead resistance
is completely out of the measurement path.
In other words, the test lead resistance is not
a part of the measurement.
Dale Cigoy, Senior Applications Engineer
Keithley Instruments, Inc. Pros and Cons
Thermistors have several distinct advan-
tages over other temperature sensors. For
Introduction temperatures. starters, they are simple to set up and oper-
Whether in industrial applications like Thermistors are also less linear than ate, using a two-wire measurement scheme.
the process industry or in laboratory set- RTDs. This nonlinearity requires a correc- They are also fast, because they can be made
tings, accurately measuring temperature is a tion to linearize it. The Steinhart-Hart equa- small and can respond to temperature chang-
critical part of success. tion helps approximate individual thermistor es quickly.
Temperature measurements are needed in curves for linearity. It describes the resistance On the down side, the non-linear proper-
medical applications, materials research in change of a thermistor as related to tempera- ties of thermistors means they need to be lin-
labs, electrical/electronic component stud- ture. The equation can be written as: earized. They also have a limited tempera-
ies, biology research, geological studies, and ture range and are fragile, because they are
1/T = A + B ◦ Jabse Service Manual Search 2024 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo