Tag Archives: refrigeration system analyzer

What’s HOT in the TOOL world! – Bill Spohn to speak at ACCA Western-PA meeting – Oct. 4

Bill Spohn from TruTech Tools will be demonstrating what’s new in the world of HVACR tools and test instruments.

Also presenting will be representatives from Ritchie/Yellow Jacket, Hilti Tools, and United Rentals.
And meet the “Student of the Month” from Triangle Tech!

Mark your calendar and be sure to join us!

Peter’s Place
1199 Washington Pike, Bridgeville, PA 15017
(Exit 55 off I79N or I79S)

3:00 pm – Board Meeting
5:30 – 6:00 pm – Social Hour (cash bar)
6:00 pm – 7:00 pm – Guest Speakers
7:00 pm – Social Hour restarts (cash bar)
7:00 pm Dinner – $40.00 (cash, check, credit card)

Dinner Selection: Prime Rib or Virginia Spots

RSVP: 724-779-1860 (phone or fax) – NO cancellations after October 2

SEE ACCA W-PA October 2012 meeting notice FOR SIGN UP FORM AND MORE DETAILS.

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Filed under A/C and Heat Pump Products, Airflow, Combustion Analysis, Customer benefits, Energy Audit, Refrigeration Products, Training, Uncategorized

Testo 550 Refrigeration System Analyzer

2016 UPDATE:

Testo has upgraded the products available. You will find the latest here, with special prices, special kits and free shipping from TruTech Tools!


TruTech Tools is proud to announce the introduction of the Testo 550 Refrigeration System Analyzer!

The Testo 550 is one of the newest and most innovative products ever manufactured at this price point for Testo. Visit us to place your pre-order for this exciting product.


The Testo 550 was engineered to be a perfect balance of features, benefits and value. Features of the 550 include high accuracy pressure transducers, low mass temperature sensors, 3-way manifold configuration and magnifying sight glass. These allow a service technician to easily evaluate both sides of the refrigeration system while displaying pressures, saturation temperatures, superheat and subcooling. All of this is packed into a rugged, compact and affordable package that will fit any technician’s budget.

Lower initial cost and low-cost of ownership
Keeping high quality standards in the forefront, Testo engineers had a daunting task to make the 550 more cost competitive without compromising the quality of the measurement. The outcome was a product that has fewer parts for quicker assembly, a redesign of the temperature sensors to make them more robust (while less expensive) and a more compact design.

Easy-to-use interface
The 550 has a separate button for almost everything – nine of them to be exact. More keys means eliminating the need to always scroll through multiple menus and sub menus to get to configuration settings. There is a power key for power, and back light key for the display, a setup key for easy configuration, mode keys for different modes, a refrigerant key to select over 31 onboard refrigerant profiles, min/max/mean key for quick system analysis, zero key for the pressure transducers and arrow keys to make selections.

Easy-to-read display
The 550 has a brighter and better defined display than previous models. Decimal points and other display characters have been enlarged for easy viewing from a distance.

Integrated hose holder and hook
The 550 has 3 brass integrated hose parks that are positional by the user to the back or front of the instrument. Residential technicians that typically set their gauges on the ground can now do so without fear of dirt, moisture or other potential system contaminates picked up by the hose parks entering the refrigeration hoses when they are in the stored position. A relief machined into the end of the hose park allows room for the Schrader depressor and a positive seal that will keep moisture from entering the hoses in the parked position. The hook is integrated into the 550 and designed so it can easily be stored if kept in an instrument case or tool bag.

User configurable units of measure
This can be very helpful if you come across foreign equipment that may not have specifications in English units of measure. The 550 can easily be configured to measure pressure and temperature in System International (SI) or the English customary system, eliminating time and error in converting to the desired units of measure.

Vacuum displayed in inches of mercury
Automatic change of units when the 550 goes into a vacuum allows the technician to easily determine when proper recovery levels are met or to set pressure switches in systems that operate below atmospheric pressure in refrigeration applications. While the 550 is rated for use in vacuum, Testo recommends the use of an auxiliary micron gauge during evacuation. The 550 does read and indicate vacuum, but does not have the resolution to display vacuum in microns.

Simultaneous measurement of superheat and subcooling
With dual temperature sensor porting standard, the 550 can be used with a second optional probe for charging and troubleshooting without the need to move the temperature sensor. Watching both sides of the system while charging allows the technician to spot problems like a faulty expansion valve at system startup before the system is overcharged. When performing any diagnostic testing, both sides of the system must be evaluated before adjustments to the charge or mechanical repairs are made.

Pressure Sensors
The Testo 550 utilizes dual ceramic thick film pressure transducers or pressure-measuring sensors, with a pressure range of -14.7 to 580 psig. Ceramic pressure-measuring cells have a measuring accuracy and repeatability that is stable over a very long time; therefore frequent calibration is not needed. The high and low side sensors are matched and selected for an operating range that will provide the highest accuracy for their desired measuring range, allowing accurate pressure measurement over the full range on either side. The pressure transducers are calibrated in regards to their zero points, coefficient of thermal expansion, and sensitivity so they can be used in wide ranges of temperatures as extra-high precision pressure transducers. Ceramic pressure transducers are designed so the pressure sensitive part is exposed directly to the refrigerant. Thanks to excellent chemical resistance, ceramic pressure transducers do not require additional protection from oils, refrigerants, or acids and additionally will withstand the shocks from normal to rough handling without ever affecting the sensor calibration. While traditional gauges require frequent trips to a calibration house to assure their accuracy (often a procedure never performed), the calibration of the pressure transducers in the Testo 550 is only recommended annually.

Altitude compensation adjustment
Like all manufacturers of digital refrigeration gauges, Testo uses a relative pressure transducer that is zeroed to atmospheric pressure. While relative pressure transducers are a very cost-effective solution, they, like bourdon tube gauges, require adjustment when used above sea level. Because the work site atmospheric pressure is typically not the same as pressure at sea level for standard air conditions compensation for barometric pressure needs to be considered for critical charging applications. In the configuration menu, the technician can now input actual barometric pressure in inches of mercury and compensate for pressure measured above sea level or that caused by changing weather conditions. This allows for a technician in an area of the country like California to work as accurately at 7000 ft as at sea level without the need for altitude corrected pressure temperature charts.

Standing pressure test with temperature compensation
During initial commissioning or after repair, a standing pressure test is required to verify system tightness over a prescribed time period. The 550 incorporates a timed and temperature compensated pressure drop test that allows the user to see the initial pressure, final pressure and the difference over time. No more marking you gauge position, tapping the gauge and measuring the time with a stop watch.

Min/Max/Mean function
When charging a system, hunting is a common problem during low loads. With the min/max/mean function in the Testo 550, the technician can easily determine what the average superheat is and verify that the system is not intermittently flooding. Pressure switch cutouts both high and low can be verified quickly and easily.

Temperature measurement
The Testo 550 uses NTC thermistors for temperature measurement with a range of -58 to 302°F. The NTC thermistor has several advantages over K type thermocouples including temperature sensitivity, electrical noise immunity, and a lower replacement cost (about 1/4 of the cost). The clamp probe has also gone through an extensive redesign to be easier to use, more robust, and lower cost. With a 1-3/8″ capacity, the standard clamp probe will easily fit around all lines on residential heat pumps and air conditioning equipment. Utilizing low mass electrically shielded thermistors, the 550 clamp probes have excellent response time and temperature measurement characteristics.

Delta Temperature Calculation
Using the Delta Temperature mode and a second temperature probe, system components like reversing valves and refrigerant liquid line dryers can easily be evaluated for excessive temperature drops and or leakage which will result in capacity losses and other associated problems. System approach can quickly be determined, by measuring liquid line temperatures and outdoor air to properly charge a system, and temperature across refrigeration coils can be verified to fall within manufacturers’ specifications.

Replaceable valve assembly
Easy to service with basic hand tools, the piston and valve packing assembly are field replaceable. The valve handle can easily be removed by pulling the retaining spring clip with a small screw driver to gain access to the valve assembly.

Leak tested
Every unit is leak tested with helium to ensure tightness. By performing this procedure we can insure that the 550 will work in both pressure and vacuum without leaks.

Oil, moisture and impact resistance
The Testo 550 is designed to withstand rigors of day-to-day service and replace the gauges that you now carry. Designed to withstand exposure to POE and mineral oils as well as refrigerant the case will not easily discolor or degrade. Because the keys can be pressed in flush, the unit easily wipes clean with a shop rag. With a rubberized housing, aluminum block and brass valves hose parks and connections the 550 is one of the most durable instruments Testo has developed.

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Trutechtools Training Tidbit

Testo 523 with hose holder

It has been four years since the US introduction of the first generation of Testo refrigeration products. Our new generation of the Testo line of refrigeration system analyzers (RSA’s) will continue to change the way the HVAC/R world troubleshoots, commissions and services AC & refrigeration systems. Although the first generation of refrigerant products was highly successful, Testo has listened to our customers’ desires to develop a product line with the diversity to meet your most demanding applications. Testo has completely retooled and reworked the refrigeration product design from the hook, which is now a quick locking carbineer, to a backlit sight glass that aids in refrigerant recovery allowing the technician to see when the last drops of liquid refrigerant are removed. Larger valve handles that can be recessed or extended make it easier for large or small hands to operate the gauge porting, and valves that can be field serviced or replaced without the need for special tools. Leading the refrigeration industry in innovative technology, Testo will again surpass your expectations in digital refrigeration technology. The next generation has incorporated a long list of new features that will increase measurement accuracy, reduce equipment-servicing time, and provide a means of tamperproof field verification, while streamlining field operations. Added this year in all instruments is the ability to print the measurement results on site via wireless printer, high stability ceramic relative pressure transducers, a large backlit display, and intuitive user operation. Three and four valve designs are available with a 3/8-evacuation port on four valve manifolds. High durability valve handles with Teflon seats, a backlit sight glass, and display, hose holder with integrated LCD protection, and in 556/560 models wireless temperature sensors and data logging. Incorporated into the 560 is also a vacuum sensor that reads in microns, “hg, or Pascal’s of pressure.  With its data storage capabilities (556/560), USB output, real-time graphic capabilities in the online mode, joined with the superior accuracy, no other product made can compete at any level.  After several years of rigorous testing in the lab and the field, the digital manifold has been proven to deliver laboratory accuracy results in demanding field service.  The multi-functionality, reliability, repeatability, and unique features set the Testo products apart from the competition.  Technicians will appreciate the ease of use, the wide range of applications, including the ability to upgrade to new refrigerants along with the wireless printing capabilities on all instruments from the Testo 523 to the Testo 556/560.  Small features like an integrated protective boot and lighter yet more robust design has not been overlooked on all models.  Future accessories for the 556/560 models including a wide variety of temperature probes, digital scale, amp clamp, and oil pressure transducer allow for quick verification of proper operation and field documentation or real-time monitoring and troubleshooting. Pressure-temperatures chart are a thing of the past, and commissioning equipment to anything less than the manufacturer’s standard will become uncommon for all Testo users.  Technicians can get more done with higher accuracy and quicker results than ever possible.  Field documentation can be done with little effort, providing any interested party with the information needed to evaluate system operation in the field or the office.   Testo has taken a quantum leap forward in AC/R measurements allowing anyone from the lab technician to the service technician to deliver consistently accurate results to owners, manufacturers and end users of air conditioning and refrigeration equipment  The Testo 523/556/560 digital refrigeration/air conditioning system analyzers are a multipurpose tool designed for every day use replacing a gauge manifold, superheat or subcooling thermometers, Pressure-Temperature charts, etc.. with a rugged hand held versatile tool.  

 Pressure Sensors

 Unlike traditional mechanical gauge sets, the Testo 523/556/560 has dual ceramic pressure transducers or pressure-measuring sensors; an advantageously used pressure measurement technology. Ceramic pressure-measuring cells have a measuring accuracy and repeatability that is stable over a very long time; therefore frequent calibration is not needed. The high and low side sensors are selected for an operating range that will provide the highest accuracy for their desired measuring range, allowing accurate pressure measurement over the full range on either side. (.5%fs) The different range of pressure transducers for the high and low sides respectively are calibrated in regards to their zero points, coefficient of thermal expansion, and sensitivity so they can be used in wide ranges of temperatures as extra-high precision pressure transducers. Ceramic pressure transducers are designed so the pressure sensitive part is exposed directly to the measured media. Thanks to excellent chemical resistance, ceramic pressure transducers do not require additional protection from oils, refrigerants, or acids and additionally will withstand the shocks from normal to rough handling without ever affecting the sensor calibration. While traditional gauges require frequent trips to a calibration house to assure their accuracy (often a procedure never performed), the calibration of the pressure transducers in the 523/556/560 is only recommended annually.  The ceramic pressure transducers or sensors can be field nulled, (often referred to as zeroing) and as good practice should be whenever refrigerant pressure is removed from the sensors, or when the hoses are purged to change refrigerant types.  A null value is different than having a value of 0, since 0 is an actual value. When a variable has no value, it considered being null. Because all standard pressure gauges are calibrated for sea level, (0 psig) if the sensor was zeroed rather than nulled, the current atmospheric conditions would not be considered. If the gauges were brought back to 0 psig outside of sea level, (a procedure often performed with mechanical gauges and some electronic) the accuracy of the gauge would be affected by the current elevation with respect to sea level. Because Testo uses a nulling procedure rather than zeroing, the instrument the sensor can be brought back into calibration in relation to the current atmospheric conditions or ambient pressure, which thus serves as a reference pressure. Quite simply, when there is no refrigerant pressure on the sensor, the reference pressure and the sensed pressure are the same. Nulling the RSA sensor brings it back to a perfect zero psig regardless of the atmospheric conditions provided the pressure is removed from the sensors. 

 Superheat and Subcooling Measurement

Thirty on board temperature pressure charts provide unparalleled detail and accuracy of refrigerant saturation temperatures, superheat and subcooling. Unlike traditional paper charts no interpolation of the temperature-pressure relationship is required.  It is now possible to measure and set superheat and subcooling with laboratory accuracy in the field as the Testo 523/556/560 reads pressures and temperatures to the tenth of a psi and tenth of a degree and automatically calculates real-time superheat and subcooling values. Temperature measurement is just as critical as temperature when commissioning and servicing equipment.  


The platinum based (platinum film on a ceramic substrate) 4-wire construction, of the spring loaded temperature sensor (Pt-100) has a very low mass (yielding a fast response) and is not affected by stray voltages that may be present on the refrigeration equipment. Unlike traditional K-type thermocouples, the sensor is electrically isolated from the RSA.  Isolating the temperature sensor electrically form the system eliminates the possibility of incorrect temperature measurement resulting from stray electrical currents or ghost voltages often present on improperly grounded refrigeration and air conditioning systems. Because the resistance of a Pt100 sensor bears an absolute relationship to temperature (unlike a thermocouple whose output depends on the difference between the hot junction and cold junction) no special compensating circuit needs to be provided in the electronics. In short, the Pt100 has a wide operating range, excellent accuracy, good linearity, excellent physical strength, long-term stability, and is the preferred sensor for all industrial processes where accuracy and repeatability are required. Additionally, Pt100 probes may be replaced without recalibration of the RSA instruments.  Sensors are available in lengths up to 40 feet. The Velcro-elastic strap provides insulation from ambient air along with positive contact to the refrigeration line from ¼” to 3” in diameter. Air and immersion probes are available to further enhance your testing applications.    


 Additionally incorporated into the system analyzer is a new dimension; time. The entire new generation of RSA products incorporates a real time clock that permits accurate documentation of the time and date readings were recorded via the wireless printer or data logging.  Testo was first-to-market with a complete line of refrigeration system analyzers that incorporate data logging, and now the first to bring wireless printing to the complete line. Owners of Testo combustion or other test equipment that already use a wireless printer will benefit from cost savings, as the printer is universal to all Testo products. Data logging (556/560) allows the service technician and or system analyst to evaluate system performance over a period of time from a snapshot to days with easy to use software, A printout of the final operating parameters on all RSA products allows for field documentation of operating at system startup or pre and post operation.   

Wireless Capability

The Testo 556/560 are both upgradeable to wireless temperature capability. Wireless technology will enable temperature measurement form remote locations for calculation of evaporator superheat at an outdoor condenser, monitoring of return and supply air temperatures for outside, or a remote outdoor air temperature. The wireless probes and the built in temperature probes can be assigned as needed for a number of field applications.    

Data Management

Wireless printing is standard in all models of the new generation of refrigeration analyzers. All measured and calculated parameters can quickly be field documented without error in seconds. Pre and post measurements allow for documentation of “as found” and “final” performance. System commissioning on new startups or major component repairs like compressor replacement are easily documented for the office and the customer.   The most significant advantages of data management and analysis are apparent when data from a Testo 556/560 is read, analyzed and managed in the Testo PC Software. It is now possible for the technician designer, engineer, service manager, or a lead technician to spot trends, benchmark systems, verify proper/design operation, provide real-time system operation to a manufacturer or other interested party in an tamperproof data format that can be graphed to provide a “digital window” into the refrigeration/air conditioning system. In the online mode, system high and low side pressures, saturation pressures, measured temperatures, along with superheat and subcooling can be viewed on an auto-scaling graph real time graphing format.  All measurements or each individual measurement can be viewed at once. System hunting, erratic operation, or other trends can be quickly spotted and documented using the optional software.  Testo has not overlooked small, but important details that make the products well suited for field use. Owners of Testo products have come to expect a rugged field service product with such features as water and acid resistance construction, a backlit displays and sight glass, user selectable units, and a battery life indicator to provide flexibility and reliability in their work.


Testo 523

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Filed under Refrigeration Products