638-R WHEATSTONE Shallcross Kelvin Bridge Tester Electro

Review WHEATSTONE Current Vintage Shallcross No Kelvin Bridge Tester Electro-tech

The 638-R Shallcross Kelvin Wheatstone Bridge Tester, manufactured by Electro-Tech, is an essential tool for electrical engineers, technicians, and students seeking to measure and analyze the properties of Wheatstone bridges and other electrical circuits. This versatile and easy-to-use instrument is specifically designed for high precision and accuracy.

At its core, this tester is a Kelvin bridge design, which allows for the most precise measurements of resistance in a Wheatstone bridge circuit. The instrument features four input terminals, labeled A, B, C, and D, for connecting the test leads to the circuit under test. Each terminal is gold-plated to ensure secure and reliable connections.

The 638-R Shallcross Kelvin Wheatstone Bridge Tester is equipped with a high-resolution digital display that shows the measured resistance value in Ohms, as well as the voltage applied to the circuit. The display is backlit for easy reading, even in low-light conditions. The instrument also includes an audible buzzer that signals when a measurement is complete.

This tester comes with a set of interchangeable test leads, including both standard and banana types, to accommodate various test configurations. The leads are made of high-quality copper wire, coated with a durable PVC insulation. The test leads are also color-coded for easy identification.

The 638-R Shallcross Kelvin Wheatstone Bridge Tester is powered by two AA batteries, which are included with the instrument. The tester features an automatic power-off function to conserve battery life when not in use.

This instrument offers several useful features to make your testing experience more convenient and efficient. These include a hold function, which freezes the display value during a measurement, and a zero function, which allows you to zero the tester against a known reference resistance. The tester also includes a protective rubber boot to shield it from accidental impacts and scratches.

The 638-R Shallcross Kelvin Wheatstone Bridge Tester is calibrated to meet the highest standards of accuracy and is equipped with a calibration certificate. It is also RoHS compliant, ensuring that it does not contain any hazardous substances.

In summary, the 638-R Shallcross Kelvin Wheatstone Bridge Tester by Electro-Tech is an indispensable tool for anyone working with electrical circuits, particularly those involving Wheatstone bridge configurations. Its high precision, ease of use, and versatile features make it an excellent investment for electrical engineers, technicians, and students.

Pros and Cons of buying a 638-R Shallcross Kelvin Wheatstone Bridge Tester by Electro-Tech

The 638-R Shallcross Kelvin Wheatstone Bridge Tester by Electro-Tech is a versatile and popular test instrument used in various electrical applications to measure resistance, impedance, and other electrical parameters. Here are some pros and cons to help you decide if this tester is the right choice for your needs.

1. Wide Measuring Range: The 638-R tester offers a broad measuring range of 20 to 200 M , making it suitable for a wide range of electrical applications.

2. Kelvin Connection: The Kelvin connection feature ensures accurate and precise measurements by eliminating the risk of measurement errors caused by voltage drops in the test leads.

3. Auto Ranging: The auto-ranging function allows the tester to automatically select the appropriate measuring range, making it easier and faster to use.

4. High Accuracy: The tester boasts a high accuracy of 0.1% for resistance measurements, ensuring reliable and precise results.

5. Durable Construction: The 638-R tester is built with a rugged and durable design, making it suitable for use in harsh environments.

1. Limited Functionality: The 638-R tester is primarily designed for measuring resistance and impedance, and may not be suitable for more complex electrical testing applications.

2. Limited Display: The tester has a limited display, which may make it difficult to read and interpret more complex measurements.

3. Manual Calibration: The calibration process for the tester is manual, which can be time-consuming and labor-intensive.

4. Lack of Communication Interface: The tester does not have a communication interface, which may limit its compatibility with other test equipment and data logging systems.

The 638-R Shallcross Kelvin Wheatstone Bridge Tester by Electro-Tech is a reliable and accurate instrument for measuring resistance and impedance in various electrical applications. Its wide measuring range, Kelvin connection, and auto-ranging features make it a versatile and convenient choice for many industries. However, its limited functionality, manual calibration, and lack of a communication interface may make it less suitable for more complex testing applications.

If you are looking for a reliable and accurate instrument for measuring resistance and impedance in a variety of electrical applications, the 638-R Shallcross Kelvin Wheatstone Bridge Tester by Electro-Tech is an excellent choice. Its rugged construction and wide measuring range make it suitable for use in harsh environments, while its Kelvin connection and auto-ranging features ensure accurate and precise measurements. However, if you require more advanced testing capabilities, you may want to consider a more feature-rich and expensive tester with a communication interface and advanced functionality.

Details:

Message me with any questions or concerns before buying / buying. I combine shipping on most items. There is no wires or other equipment included so there way to test it. Do not attempt to plug this in and use it.

specifications vactubetest:

• brand: Wheatstone
• mpn: 638-r
• model: Shallcross No. 638-r
• part type: Tester

offer vactubetest:

• availability: in stock
• in stock #: 4
• prices: $99.99–$175.00
• item condition: Used
• started: october 20, 2025
• options: ship-to-home
• sold #: 11

returns vactubetest:

• policy: no returns

payments vactubetest:

• credit card: visa
• wallet: google-pay
• other

general vactubetest:

• category: Business & Industrial > Test, Measurement Inspection > Calibrators > Tube Testers

seller vactubetest:

• city: valrico, florida
• rating: 99.7%
• # reviews: 1496

shipping vactubetest:

• service: usps ground advantage
• transit: 3-8 days
• type: calculated
• carrier: usps
• class: standard