Armfield - Thermodynamics - TH Series

The TH1 Armfield Temperature Measurement and Calibration unit is designed to introduce students to temperature and how different techniques can be employed to measure this variable.

The thermometric properties and characteristics of temperature measuring devices can be investigated and the devices calibrated using precisely generated fixed points and an accurate reference thermometer.

Key Features

• A benchtop unit comprising a hypsometer/hot water bath and ice flask, which generate accurate fixed points and variable temperatures. An accurate platinum resistance thermometer (PT100) with five-point NAMAS calibration certificate and temperature indicated directly in °C is included for reference
• Other temperature sensors include: Platinum resistance sensor, K-type thermocouple, thermistor, bimetallic and liquid in glass thermometers
• Used to investigate thermostatic properties and characteristics of temperature measurement devices
• The hypsometer uses condensing water to generate an accurate calibration point. It is heated by a pair of 1kW electric heating elements with variable power control and overtemperature protection
• The electrical console houses all the necessary electronics with appropriate protection devices and an RCD. A digital meter with selector switch displays all thermometric properties and temperatures measured. Corresponding signals are routed to an I/O port for connection to a PC using the Windows operating system, via an interface device provided with the optional software
• An optional interface device and educational software package is available
• A comprehensive instruction manual with a range of fully detailed laboratory teaching exercises is included

The TH2 Armfield Pressure Measurement and Calibration Unit has been designed to introduce students to the physical science of pressure and how different techniques can be employed to measure this variable.

Different fixed pressures are generated using a simple Deadweight Pressure Calibrator for the purpose of calibrating the measuring devices. A Bourdon-type pressure gauge and electronic type pressure sensor are connected to the calibrator to enable their characteristics, including accuracy and linearity, to be determined.

Key Features

• A benchtop unit comprising a simple Deadweight Pressure Calibrator with weights to generate a range of predetermined pressures. This is connected to a Bourdon gauge and electronic pressure sensor. The Bourdon gauge incorporates an arbitrary scale in addition to the pressure scale and a clear acrylic front face enables observation of the Bourdon tube and the operating mechanism. A reservoir with isolating valve enables the calibrator, Bourdon gauge and pressure sensor to be easily primed
• An electrical console houses the necessary electronics with current protection devices and an RCD for operator protection. A digital meter with selector switch displays the output from the pressure sensor, as well as the conditioned reading in engineering units. Corresponding signals are routed to an I/O port for connection to a PC. An optional interface device with educational software package is available
• The Deadweight Pressure Calibrator, Bourdon gauge and pressure sensor are mounted on a common PVC baseplate. The electrical console is free-standing
• Pressure sensors, manometers or Bourdon gauges other than those supplied can be calibrated over the range 20 kNm^-2 to 200 kNm^-2
• A comprehensive instruction manual is included with a range of fully detailed laboratory teaching exercises

The TH3 Armfield Saturation Pressure Apparatus has been designed to introduce students to how the temperature of water behaves at its boiling point with variation in the absolute pressure.

The TH3 offers all the features of a Marcet Boiler and adds the capability of determining the quality of wet steam, thus enhancing the understanding of the underlying thermodynamic principle.

Saturation curves can be obtained by the student and compared with published steam tables. The quality of steam exiting the apparatus can be determined using a throttling calorimeter connected at the point of discharge.

Key Features

• A benchtop unit comprising a boiler vessel and pipe loop with a pressure-relief valve to limit the operating pressure to eight bar gauge. A sight glass on the front of the boiler enables the boiling patterns to be observed and a Bourdon-type gauge indicates the pressure in the apparatus at all times for safe operation
• A throttling calorimeter mounted adjacent to the pipe loop enables the condition of the saturated steam to be determined by measuring the temperature of the steam following throttling to atmospheric pressure. Temperatures in the pipe loop and inside the throttling calorimeter are measured using PRT sensors and pressure in the loop is measured using an electronic pressure sensor
• An electrical console houses the necessary electronics with current protection devices and an RCD for operator protection. A digital meter with selector switch displays all sensor measurements. Corresponding signals are routed to an I/O port for connection to a PC. An optional interface device and educational software package is available
• The boiler is heated by a pair of 500W electric heating elements with variable power control and overtemperature protection
• A comprehensive instruction manual is included with a range of fully detailed laboratory teaching exercises 

Recycle is a simple phenomenon, which occurs in many aspects of everyday life, but is also a concept that can lead to confusion in engineering applications when combined with other principles such as mass / energy balances and the use of the steady flow energy equation.

The Armfield Recycle Loops apparatus has been designed to demonstrate clearly, both visually and experimentally, what recycle is and to enable mass and energy balances to be performed under steady state and unsteady state conditions. The application modelled is typical of a heating arrangement in the chemical, food or pharmaceutical industries whereby the temperature of a product is raised or lowered offline by recirculating some of the product through a heat exchanger.

The practical training exercises are appropriate to heat transfer and thermodynamics courses and the training of technicians and engineers in those disciplines.

Key Features

• A bench top unit comprising a vacuum formed ABS plastic plinth with integral electrical console on to which is mounted a through pipe with a recycle loop, which incorporates a circulating pump and heater
• A pressure regulator with filter at the inlet to the apparatus minimises the effect of fluctuations in the cold water supply pressure. Water in the recycle loop is heated by a 2kW electric heater with overtemperature protection. Flow in the loop can be varied from 0 (no recycle) to 3 l/min. The through flow of water can be varied from 0-1.5 l/min
• Temperatures at the entry to the system, at the exit from the system and inside the recycle loop are measured using K-type thermocouples. Flow rates at corresponding locations are measured using turbine type flow sensors. A reservoir with self-sealing fittings enables the volume of the loop to be changed
• All electrical circuits are protected by appropriate protection devices
• The console incorporates a digital meter with selector switch, which displays the temperatures and flow rates measured. Corresponding signals are routed to an I/O port for connection to a PC 
• An optional interface device and educational software package is available
• A comprehensive instruction manual is included with a range of fully detailed laboratory teaching exercises

The Armfield Expansion Processes of a Perfect Gas apparatus has been designed to introduce students to a range of basic thermodynamic processes using air as the working fluid.

Key Features

• A small-scale unit designed to introduce students to the properties of a perfect gas using air to demonstrate basic thermodynamic processes
• The hardware consists of two floor-standing interconnected rigid vessels, one equipped for operation under pressure and the second under vacuum. Appropriate valves and tappings are fitted to enable different thermodynamic processes to be evaluated. An electric air pump is supplied to enable pressurisation or evacuation of the vessels as required for the different exercises. Each vessel incorporates a fast response thermistor sensor to monitor the temperature of the air and connection to a piezoelectric pressure sensor
• All power supplies, signal conditioning circuitry etc, are contained in a simple electrical console with appropriate current protection devices and an RCD for operator protection. Readings from the pressure sensors and thermistors are displayed on a common digital meter with selector switch. A port on the console can be used to connect to a PC using an optional interface device included with the educational software package . Alternatively the signals can be connected to a user-supplied chart recorder
• A comprehensive instruction booklet describing how to carry out the laboratory teaching exercises is included