ParrNotes Newsletter Vol.3 No.1


A Quarterly Newsletter of Parr Instrument Company | March Edition 2016 | Vol. 3 No. 1


Features and Benefits
Service Tips
Controller Section
Application Awareness
Parr Team Member Focus
Upcoming Events

Features and Benefits

Liquid Metering Pumps

A pump is required to transfer a liquid from a lower pressure environment to one of higher pressure. There are many different types of pumps. Among the most common are various types of piston pumps. In most industrial situations, where high flow rates are required, a reciprocating piston moves fluids in and out of a chamber, called the pump head, which has ball check valves at each connection. See Figure 1 below. In order to change the flow rate of these large pumps, the piston stroke length is varied while maintaining the same motor speed.

Pump head with inlet and outlet check valves
Figure 1
Pump head with inlet and outlet check valves

In the laboratory setting, a piston pump is also used but it is of a style borrowed from the analytical world of High Pressure Liquid Chromatography. Known as HPLC pumps, here the flow rate is varied by changing the motor speed. A stepper motor is connected to an eccentric cam that provides for a very smooth delivery and a very rapid refill, minimizing any associated pressure pulses.

Parr has a standard selection of HPLC-style pumps to meet the needs of most customers. The available flow rates are either 0-10 mL/min or 0-40 mL/minute. The higher flow rates are available in pumps that can deliver liquids up to 1500 psi (100 bar). The pumps with the lower flow rate can deliver at pressures to 5000 psi (350 bar). Both of these pumps are available with faceplate operation or with remote control capabilities, such as from a 4871 Process Controller. There is also a lower cost pump for 0-10 mL/minute flow rate at a maximum pressure of 2000 psi (135 bar). These pumps are summarized below.

Parr HPLC-style Liquid Metering Pumps
 Part No. Max. Pressure psi  Flow Rate mL/min. Volts
 A2286HC 2000 0.01 – 9.99 115/230
 A2287HC 5000 0.01 – 9.99  115/230
 A2288HC  1500 0.04 – 40.0  115/230
 A2289HC* 5000 0.01 – 9.99 115/230
 A2290HC*  1500  0.04 – 40.0 115/230
*Can be controlled remotely, 0 – 10V

Parr can also supply pumps with heated or chilled pump heads for special applications.

Additionally, there are other pumps that are commonly found in laboratories.

For use at pressures below 100 psi, tubing pumps (such as Masterflex Peristaltic Pumps) offer an extremely wide flow range, with models from microliters/min to liters/minute. These pumps are comparably priced to the HPLC-style pumps. There are also valveless pumps, from Fluid Metering Inc., that offer excellent precision at pressures below 100 psi and flow rates from 0.1 to 2000 mL/min.

For high precision, wide range of flow and use at high pressures, syringe pumps are often the pump of choice. Teledyne Isco, for example, offers pumps for operation at pressure up to 2000, 3750, 5000, 10000, and 20000 psi and continuous, pulseless flow rates from 1 µL/min to to 400 ml/min. These pumps can also be used to deliver slurries with liquid/solid mixing provided by an air-driven Parr magnetic drive.

For all your pumping needs, contact the Parr customer service representatives and let us build one for you.

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Service Tips

How to get Magnetic Drives to Spin Faster

The majority of Parr stirred reactors have a belt and pulley system installed between the motor and the magnetic drive. Our most typical arrangement is one in which the drive pulley (above the motor) is about 1/3 the diameter of the driven pulley (above the magnetic drive). This arrangement approximately triples the available motor torque but reduces the stirrer speed to about 600 RPM leading some customers to ask: How do I get my Mag Drive to Spin Faster?

Alternative drive pulleys are available to allow for increased stirrer speeds (as seen in See Figure 2 below). Note that this will be accompanied by an equivalent decrease in available torque for stirring more viscous materials. The size of the driven pulley remains constant.

Standard 1700 rpm Pulley and Motor Setup
Figure 2
Standard 1700 rpm Pulley and Motor Setup

An example of a common occurrence is the use of the Parr Gas Entrainment Impeller. Our studies with air and water have shown that this impeller functions best in the 800 to 1200 RPM range. Retrofitting this impeller to a reactor with a 600 RPM impeller, will require a change in drive pulley and its corresponding belt.

Customers should consult their Operating Instruction Manual for available pulleys and required belts for their specific system. Pulleys are available for 600, 800, 1000, and 1700 RPM for our most common reactors.

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Controller Section

Maintaining 4840 Controllers

Parr controllers have been around for a long time. Some older controllers are not serviceable, and others are only serviceable to a certain degree. This article will cover the ability to service series 4840 Controllers.


Series 4840

This series was first developed in 1979, and utilized until 2008. The chassis, switches, and display panels remained virtually unchanged during this time. The temperature control meter changed a number of times. We offered three models:

4841: Proportional controlled temperature.

4842: Setpoint controlled temperature with PID control.

4843: Setpoint controlled temperature with PID control and optional ramp and soak capability.

4840 Controllers from 1979 to early 1990’s

4871 Controller from 1979 to early 1990's The 4841 with a dial type proportional module was offered until the early 1990’s. Turning a knob would adjust the heater output to near the setpoint, and you had to adjust the reset potentiometer to give the output a little kick to reliably go to the setpoint.
4872 Controller from 1979 to early 1990's The 4842 utilized the LFE controller, which had digital setpoint PID control but not ramp and soak capability. The LFE model 2000 is shown.
4873 Controller from 1979 to early 1990's The 4843 used the LFE model 3000 with digital PID setpoint control and included the added benefit of ramp and soak.

4840 Controllers from mid-1990’s to 2003

4842 Controller with Watlow 989 from mid 1990's to 2003 The 4841 was retired by the mid-1990’s as the cost of digital PID controllers came down. The Watlow controller was introduced at this time. The 4842 with Watlow 989 is shown here.
4843 Controller with Watlow 981 from mid 1990's to 2003 The Watlow 945 and Watlow 981 (for the 4843 with ramp and soak) were also used around this time.

4840 Controllers from 2003-2008

4843 Controller with Cal 9500 meter from 2003 to 2008 In 2003, the state of small PLCs was such that it didn’t cost any additional money to buy a meter with ramp and soak capability. At this point we changed to a Cal 9500 meter which had ramp and soak built into the basic meter. The 4842 was retired, leaving only the 4843 with the Cal 9500.

4840 Controllers from 2008-present

4848 Reactor Controller shown with PTM, MCM, PDM, and HTM Modules installed. The 4848 has a redesigned chassis and has replaced the analog meters found in previous models with digital control meters. The temperature control meter has an excellent autotuning feature, PC communication, and superior temperature control across a wide range of conditions.
4848B Reactor Controller with six panel meters The 4848B is similar to the 4848, but with a larger chassis and space for up to six additional modules.

Serviceability of the 4841, 4842, and 4843 Controllers

Most of the components in the 4840 Controllers are readily available. Switches, solid state relays, motor boards, wiring, etc. are all available for servicing. There are a few notable parts that are not available, listed below.

TDM, PDM, HTM Meters

The 4841, 4842, and 4843 Controllers all used analog displays for the Tachometer, Pressure, and secondary Temperature. These TDM, PDM, and HTM displays were manufactured by Gil Instruments. We stopped using these types of displays in 2008 when we switched to the 4848 Controller. Since then, there has been limited availability of certain Gil displays. Please inquire with Parr Technical Support for all replacement meters from the 4840 Series.


The metal components of the chassis are available, but we do not stock them. They can be ordered with an approximate 3-4 week lead time.

We are unable to get the side panels of the chassis because the molding operation that was used to construct these is no longer available.

Primary Temperature Meter

The original dial type, LFE, and Watlow controllers were discontinued by their manufacturers and are no longer available. A retrofit kit to install a Cal 9500 controller is available as part number A3100HC for the 1/8 DIN controllers and the A3100HC2 for the 1/4 DIN controllers.


When to Replace or Repair

The typical lifespan of a controller is ten years. When considering the serviceability of a controller older than this, it may be more beneficial to replace the controller with one of our latest models.

Please contact us for further information on servicing Parr controllers.

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Application Awareness

Oxygen Bomb Calorimetry

TN104Oxygen combustion calorimetry has six major areas of application:

  • Fuels and Alternative Fuels
  • Waste and Refuse Disposal
  • Food, Metabolic, Medical Studies
  • Propellant and Explosive Testing
  • Thermodynamic Research
  • Educational Training

Download our recently revised Combustion Calorimetry Applications Tech Note to read about the history of bomb calorimetry and in depth details on applications for combustion calorimetry.

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Parr Team Member Focus

Vern Moon, Senior Engineer

Vern Moon

In this edition of ParrNotes we are celebrating a key member of our engineering department and our company as Vern Moon prepares for retirement this April.

Vern has been with Parr Instrument Company for 32 years. He began his Parr career in 1984 as an Engineer where he was hired for New Product Development on the Calorimeter side of the business. With the growth in the Pressure Reactor business, very quickly Vern’s focus was shifted to “Custom Reactor Systems”, product upgrade, and new product design.

In Vern’s current role as Senior Engineer he is involved with research and development projects, custom orders and proposals, regulatory requirements (electrical and mechanical) for our product lines, as well as providing support for our dealers, customers, and all internal departments.

During his career, Vern has received two patents for inventions he has worked on at Parr Instrument Company and International Harvester Company.

Vern Moon receiving 30 Years of Service Award from Jim Nelson
Vern Moon receiving his 30 Years of Service Award from Jim Nelson in 2015

Some of the highlights of Vern’s job that have kept him at Parr are the variety of unexpected tasks that surface from all aspects of our business and the constant shuffling of priorities to ensure we are meeting our mission statement. Vern has also enjoyed seeing the continual improvement to Parr’s configurator/generic bill of materials to increase velocity and streamline Sales input to provide effective communication to Manufacturing, Purchasing, Assembly, and Shipping.

Vern is from Port Byron, Illinois where he resides with his wife Stacey (Parr’s Director of Quality Assurance & Operations Manager). After retirement Vern looks forward to having more time for hunting and fishing on their 40+ acres of land and most importantly to spend with his children and grandchildren.

When asked what he will miss most about working at Parr, Vern said “I will miss working with the variety of one of a kind systems we create, developing new products to increase our market, and the people at Parr. I will truly miss the Parr family atmosphere that you can’t find in big companies.

Vern, your Parr family will miss your vast expertise, attention to detail, and friendly disposition. We wish you a very long, happy, and healthy retirement!

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Parr Instrument Company building in Moline, Illinois
Parr Instrument Company in Moline, Illinois


Do you have a customer or new team member in need of training for Parr Instrument Company products? Could you benefit from a refresher course? We provide dealer and customer training free of charge at our facility in Moline, Illinois.

The following training sessions have already been scheduled:

  • April 11th to April 15th, 2016
  • September 12th to September 16th, 2016

Alternate dates may be available.

Please see our Dealer Training page or contact us for more information.

We look forward to your visit!

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Upcoming Events

Parr's Booth at ACS Fall in Boston
Parr’s Booth at ACS Fall in Boston

251st American Chemical Society National Meeting & Exposition
March 13 – 17, 2016
San Diego, California
Booth #1401

We are pleased to be able to offer you a complimentary Exhibit Hall Pass to visit us at the 251st ACS!

Organic Reactions Catalysis Society
March 27 – 31, 2016
Miami, Florida
Booth #2

Korea Lab
April 26-29, 2016
Kintex 2, Korea
Look for our representatives from MK Science Co., Ltd. at Booth #10I407

May 10 – 13, 2016
Messe München GmbH
Look for our representatives from Parr Instrument Company GmbH

View our complete 2016 Trade Show schedule.

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