Cal Test Electronics reintroduces the CT3687 100 MHz High-Voltage Differential Probe — brought back by popular demand. Known for its proven performance and robust design, the CT3687 is once again available to support engineers needing safe, accurate differential measurements up to ±1,400 V.
Differential probes allow an earth-grounded oscilloscope to safely measure voltage between two floating points, where neither is at ground potential. The CT3687 converts those signals into ground-referenced outputs that can be safely displayed on any oscilloscope with 1 MΩ input impedance. With switchable attenuation (100x / 1000x), a wide 100 MHz bandwidth, and ±1% accuracy, the CT3687 enables high-resolution measurements in power electronics, motor drives, and energy systems. At 100x attenuation, the probe supports ±140 V, and at 1000x, it supports ±1,400 V differential and common-mode input voltages.
The CT3687 includes four AA batteries for immediate operation and also supports the CT3723 universal power adapter and the CT4122 USB power lead (both optional), offering flexibility in field and bench environments.
Backed by a one-year warranty and compliant with IEC 61010-031, RoHS 2, and REACH, the CT3687 is a rugged, ready-to-use solution trusted by engineers across a wide range of high-voltage applications.
Features:
±140 V (100x) and ±1,400 V (1000x) differential input
100 MHz bandwidth (-3 dB)
Switchable attenuation: 100x / 1000x
±1% accuracy with high CMRR (-80 dB @ 60 Hz)
Compatible with oscilloscopes (1 MΩ input)
Power and over-range indicators
Operates on AA batteries (included)
Optional power via CT3723 (adapter) or CT4122 (USB)
Includes hook probes and user manual
One-year warranty
RoHS 2 and REACH compliant
Specifications:
Bandwidth: 100 MHz (-3 dB), 3.5 ns rise time
Differential Input Voltage: ±140 V @ 100x, ±1,400 V @ 1000x
Attenuation Ratio: Switchable 100x / 1000x
Accuracy: ±1%
CMRR (typical): -80 dB @ 60 Hz, -50 dB @ 1 MHz
Power Options: 4 AA batteries (included), optional CT3723 adapter or CT4122 USB lead
Since 1995, Cal Test Electronics has been serving the electronic and electrical markets with an extensive line of quality test accessories and a commitment to total customer service. We evolved for the specific purpose of providing customers with products they need to get their tasks completed. Our mission is to provide you with both a quality product and 30 years of expert knowledge so that you can remain focused on your goal. Our job is to make your testing life easier. If you are in the electronic, electrical, maintenance or process control industries, we offer the most comprehensive lines of test accessories. With over 3,000 items in 7 product categories, there is almost no test accessory challenge Cal Test cannot meet.
For additional product information, cross-references, or other test accessory information, visit www.caltestelectronics.com..
![CT3687_72dpi[1]-lg[1]](https://14566053.fs1.hubspotusercontent-na2.net/hub/14566053/hubfs/CT3687_72dpi%5B1%5D-lg%5B1%5D.jpg?upscale=true&width=1120&upscale=true&name=CT3687_72dpi%5B1%5D-lg%5B1%5D.jpg)