About two years ago, Agilent began building up a line of digital multimeters (DMMs), and today offers a roster of 11 instruments ranging in price from $99 to $450. As multimeters go, they’re quite capable; all models are equipped with a rear-panel infrared (IR) port for communication with a PC facilitated by a $30 IR-to-USB cable. By adding free data-logger software, users of these meters have a handy means of documenting measurements. The IR port serves Agilent’s purposes by making the meters dead simple to calibrate before shipping.
The IR port gives Agilent’s DMMs a leg up on many competitive models, which generally have no connectivity of any kind. An IR port is nice to have, but wouldn’t a wireless link would be better? To that end, Agilent has come up with a little accessory that in itself is no great engineering feat. But the U1177A Bluetooth adaptor, a $48 add-on that plugs directly into the IR port, opens a great big door into use models for DMMs that have never before been possible (Fig. 1). At the same time, it brings the DMM, which has been around for decades, into the realm of modern technology.
Snapping the Bluetooth adaptor into the IR port converts the serial IR data into a two-way Bluetooth link (Fig. 2). After pairing the adaptor with your PC or Android-based tablet or smart phone running one of the two Android applications that Agilent has provided, you can start measuring and the meter will automatically transmit the data to the Android device. Each of the apps will permit connection of up to three separate Agilent DMMs, provided all are equipped with U1177A adaptors.
The two mobile apps provide for basic monitoring and data logging, respectively. The “mobile meter” app enables basic, real-time interaction with connected DMMs on your Android device’s screen. Meanwhile, the “mobile logger” app simplifies data logging and remote monitoring. Agilent also offers a free data-logging app for Windows PCs.
A side note: Agilent chose to develop this functionality for Android devices and not for the iPad/iPhone not out of any real preference for Android, but because Apple does not permit two-way communication with its devices through apps. Besides, says Tak Tsang, business development manager for Agilent’s Basic Instrument Division, “techs don’t want to buy iPhones anyway,” preferring instead the openness and moddability of the Android OS.
So what can you do with this adapter on your Agilent DMM and Android device? For starters, with Bluetooth’s 30-foot range and the mobile-meter app, you can walk away from your DMM on the bench or at a field site and still see how your ongoing measurement is doing. As mentioned, you can see readings from as many as three DMMs at once at that distance.
Further, you can share measurements with others via email or SMS as either an image or text. What’s really cool is that in the future Agilent plans to add alarm functions. So if a measurement goes out of a preset range, for example, the app can be instructed to use your Android phone to call you at another number (your desk, for example, or perhaps a hotel in Maui).
With the mobile-logger app in play, the focus shifts to remote data logging. The same range and number of meters applies as with the mobile-meter app. The app will log and graph measurements for your meter(s) and also provides a math functions so that readings can be added to or subtracted from one another.
With the ability to set up a meter and read data remotely, the applications of a DMM become much broader. In the lab, the adaptor eliminates wiring of USB connections and allows easy data logging, graphing, or documentation. On a testing ground, DMMs may be used to monitor circuits on mobile platforms (automotive or pleasure craft), or in hard-to-reach locations such as the business end of a windmill. It also affords a measure of safety in removing personnel from high-voltage environments or from close proximity to moving parts.
Agilent intends to work toward an open-source model for the Android apps and hopes to work cooperatively with users in developing specialty apps. Stay tuned for more on this front.