Test equipment is essential for the operation of most electronic manufacturers and service providers, and most engineers develop a kind of “relationship” of sorts with that favorite signal generator or oscilloscope and may even arrive early to the workplace to get the first shot at using the favorite test equipment. Of course, it would be ideal if a company could equip every workstation with a full lineup of test equipment, so that an engineer knew that the test equipment was waiting for them, and not vice versa. But, the cost of test equipment can add up quickly, especially when trying to equip everyone in a design team with a full set of test gear. For many companies, it may be more practical to carefully consider when to buy a new piece of test equipment and when it might make more sense to rent the equipment needed for a set of measurements. But when to rent and when to buy?
Perhaps the simplest way to decide if a test instrument should be rented or bought is by measuring the need for the functions provided by that instrument. In fact, sometimes, it is the number of functions offered by an instrument that will determine the need for that instrument within a company. Obviously, an oscilloscope with 1-GHz bandwidth will be limited in the number of measurements it can perform compared to an oscilloscope with a 20-GHz or greater bandwidth. The costs between the two will differ as well, but a workhorse instrument such as a digital storage oscilloscope (DSO), especially one with a wide bandwidth, can take on many of the measurement chores at a company and is generally a safe and practical investment when purchasing new test equipment.
Purchasing rather than renting such a versatile instrument as a wide-bandwidth oscilloscope also means that it is always available, even for measurements which may not be considered “standard” for a device under test (DUT). For example, while a 4-GHz oscilloscope may provide accurate analysis of a DUT such as a CW or pulsed RF power amplifier through 4 GHz, it is not capable of measuring the harmonic behavior of such a DUT, while a 20-GHz oscilloscope can provide details on at least the first two harmonics of a 4-GHz power amplifier.
Similarly, the needs of engineers in a company’s design and production departments for generating test signals can help determine whether to rent or buy a test signal source such as an arbitrary waveform generator (AWG) or arbitrary function generator (AFG). While the test requirements for production-line DUTs may be well known and well defined, the requirements for testing new designs are largely unknown, including the types of test signals that will be needed to discover the limits of a new DUT, such as a power amplifier. Investing in the purchase of a test signal source that can generate all the test signals required for production-line testing makes sense, whereas the need for the more exotic test signals possible from a higher-end, higher-sampling-rate AWG or AFG may not be as great or as often. In such a case, the test signal sources that can generate all the test signals needed for full production would be purchased and the higher-end test signal sources that would produce the higher-frequency, more complex test signals perhaps only used occasionally in the research and development of a new product would be better suited for rental.
The frequency of a measurement, in more ways that one can help decide when to rent versus when to buy the test equipment. How often a measurement is performed, for example, is a good indication of whether the test equipment for that measurement should be a permanent fixture within the company (purchased) or if it can be added to the test-equipment racks on an as-needed basis (rented or rental with equity). The frequency at which a DUT is being characterized may also determine when to rent or when to buy the test equipment, since the need for evaluating a product at 40 GHz and above may surface only rarely compared to the need for a test signal source and spectrum analyzer that can reveal the spectral qualities of a DUT through much lower frequencies, such as 10 GHz.
In general, the test and measurement needs of a company’s different engineering departments will determine when to rent or when to buy, especially in terms of test equipment. For example, for a company that performs contract work, the type of testing that is required according to the terms of the contract may not be ordinarily performed at the company so that it would not make sense to purchase such test equipment just for contract work. In addition, the terms of the contract may make it possible to build the cost of the rented test equipment into the contract. For contract work especially, renting test equipment helps to avoid a situation where test gear has been added to a company that was very much needed at one time but is hardly used after the fulfillment of the contract.
Another case where rental rather than purchase may make more sense is for some of the measurements required during a long-term product development cycle. For a product design and development schedule that exceeds one year, certain types of test equipment, such as test signal sources and analyzers for electromagnetic compatibility (EMC) and electromagnetic interference (EMI) compliance testing, may not be needed until the latter stages of the product development cycle, especially when such equipment would not be used for other DUTs within the company. In this case, it may make more sense to determine the EMC/EMI compliance test needs for the product during its latter stages of development so that the required test equipment can be added through rental. In doing so, the suitability of different test instruments can be evaluated for each set of measurements, and the rental of the equipment can serve as a form of “audition” prior to purchasing the equipment when it has been determined that the measurements will be performed with enough regularity to merit the purchase of the equipment.
Renting test equipment is always a practical way to take a “first look” at a new piece of test equipment, especially something like an AFG or AWG which may require some creative programming to achieve the best results. Renting is a cost-effective way to determine if an instrument is what is needed for a measurement and, perhaps as important, if it is the type of instrument that can help a company’s workforce. In short, if the amount of time that an instrument is being used could be plotted, then those instruments being used the most should be bought while those that are used only occasionally should be rented.
If you want to rent or purchase test equipment, please visit Axiom’s website at www.axiomtest.com to view our inventory. If you would like help selecting the right equipment for your project, contact Axiom Test Equipment’s sales department at firstname.lastname@example.org, or by calling an Axiom sales representative at 760-806-6600.