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USB Voltmeter
USB voltmeter is a small module to measure voltage.The USB Voltmeter sends measured data to PC via USB and a computer displays the data on a monitor. The voltmeter is supplied with USB cable voltage +5 V.It does not need other external power supply.

This web page presents four types of USB voltmeters. They differ from each with measured  range, accuracy and resolution.

Type Range Resolution Error Usage
USB Voltmeter Type 1 -50 V to +50 V  0,1 V  max 0,1V simple voltage monitoring (simple, cheap)
USB Voltmeter Type 2 -50 V to +50 V  0,001 V  max 0,001 V standard voltage measurement
USB Voltmeter Type 3 -5 V to + 5 V  0,000 15 V  max 0,15 mV 10 x smaller range, 10 x better resolution
USB Voltmeter Type 4 -0,2 V to + 0,2 V  0,000 015 V  max 0,015 mV for sensors, bridge...etc , high resoluion
USB Votmeter Type  5 -50 V to +50 V  0,001 V  max 0,001 V full galvanically isolated from PC (comming soon)

Next types :
USB Voltmeter - 4 channel 0 V to +50 V              0,1 V               max 0,1V     common ground,  positive value only               

USB voltmeter
USB Voltmeter Type 1 - Type 4
Description : Technical parameters:
Voltmeters  Type 1 - Type 4 use external 16-bit A/D converter. All voltmeters have excellent linearity and very low error. Hardware for these voltmeters is almost identical. Size :
Connector :
Impedance :
Speed :
45 x45 mm
mini USB
0,5  MOhm
6 times/sec

Pictures : USB Voltmteter ( click to enlarge images )

USB Voltmeter USB Voltmeter

Voltmeters Type 1 to Type 5 can measure both positive and negative voltage. Input impedance is about 0.5 MOhm. At the input is voltage-divider (see the schematic picture). Voltmeters T1 to T4 have differential input and they are not isolated from PC. Full galvanically isolated from the PC is Type 6 (available 20 dec.2010).

It is possible to use more voltmeters in parallel. USB standard allows you to connect up to 128 USB devices. All voltmeters are so-called "HID device" and use USB drivers installed default in Windows. It's plug and play system.

To display the measured value is used by software USBMeasure. It is a Windows application. It is also supplied API + source code (see software page).

System requirements: Windows XP or higher, free USB port.
Voltmeter accuracy test
watch a video

USB voltmeter 4-channel
USB Voltmeter  4-channel
Usage : Technical parameters:
Voltmeter Type 4 is a 4-channel voltmeter designed to easily measure the voltage. It is a version with 10-bit internall A/D converter. Range :
Resolution :
Impedance :
Error :
Speed :
0V to + 50V
1 MOhtm
0,1 V max
20 times/sec

Pictures :  USB Volmteter Type 4  ( click to enlarge images )

Voltmeter Type 4 has measuring range 0V to +50V . The resolution is 0.1 V in entirely range. All inputs have common ground. Voltage is measured 20 times/sec.

Voltmeter Type 4 has 4 independent inputs amplifiers and each channel measure in the range 0-50V. Measured values are displayed on the monitor.

If it is necessary to measure more than four channels, it is possible to connect more of these 4-channel voltmeters. But a user will have to make his own application from the supplied API.

Voltmeter is type plug and play. There is no need to install any USB drivers.
voltmeter Type 4

The voltmeters are  galvanically connected with a PC (except Type 5 ).  It is possible to simultaneously connect up to 127 USB voltmeters. Instalation of USB voltmeter is easy. When you plug the voltmeter first time into the USB port a new message appears : "Found new hardware" and "Hardware is ready for use" and voltmeter and is ready for use.
Software + API
voltmeter is supplied with software USBMeasure.exe. It is standard software for measuring with the USB voltmeters.

We also offer API (USBMeasure.dll) for easy and quick creation of custom applications. API task is to ensure measurement and data communication with PC. For that purpose has API all the necessary features. Developer only add your own functionality and make their own graphical interface (GUI).

The API is implemented as a COM component. This component can be used in all known programming languages. It was tested with C#, C++  , visusal basic, delphi and javascript. 

Source code examples are in the program help.
USB voltmeter software
USB Voltmeter -> PC communication
USB Voltmeter - HID device.
All voltmeters are HID devices - Human Interface Device. These devices use USB drivers already installed by default in Windows.  It's the same type of communication as a PC communicates with the USB mouse or USB keyboard. This applies to all versions of Windows - from windows XP above.
USB voltmeters have their own unique VID & PID numbers,so there is no possibility of collision between other USB devices.