Clinical Trial Packaging & Storage
Due to all these things, you can increase the intensity of the results to a lot extent and it will make you feel happy and you will get the results that you have never imagined at any cost. UniCel DxC systems are built to deliver maximum productivity for your laboratory. They are also used in the care of wooden musical instruments such as pianos, guitars, violins, and harps which can be damaged by improper humidity conditions. If you can't find what you are looking for, call us today at With points, the timing will drift; power and fuel economy will suffer. No air separator is necessary nor a charging pump. Have been searching for a replacement from a previous overpriced product.
Used Chemistry Analyzer Equipment
PEM, PEM features a brushless DC motor, differential temperature controller, and is available with two sizes of pump head models: Flow rates range from 0. Available in 12 VDC configuration only. PM, PM features a brushed DC motor, differential temperature controller, and is available with two sizes of pump head models: Flow rates range from 2. Typically, a solar water heater will run for 2, hours per year in mid-latitude countries consuming 80 watts of grid electricity during operation.
The added pressure drop of the smaller diameter tubing is easily overcome by this powerful little pump. No air separator is necessary nor a charging pump. Not only is it economical to use the Solar Pump, but by using solar energy you reduce the pollution for which you are responsible when using a grid-connected pump.
To produce 4, kilowatt-hours of electricity in a modern steam power plant will result in four tonnes of carbon dioxide emissions into the atmosphere!! All fittings, hoses and sensors sold separately. The pump is a brass body, vane-type, positive displacement pump. Should your application require fittings or hoses of a different size, metric or imperial, substitutions are possible.
Please contact us for more information. No parts are subject to corrosion - all wetted parts are stainless steel, brass or carbon. It is also self-priming, with a maximum suction lift of 2 meters 6 feet. As the electro-magnetic field rotates, so does the pump rotor causing the pump to circulate. Commutation of the brushless DC motor is achieved by an on-board motor control circuit that utilizes hall effect sensors and a motor control IC. The motor control circuit also features a built-in differential temperature solar controller with linear current booster for a complete solar water heater control package.
The instrument can be made more sensitive by removing oils from the hair, such as by first soaking the hair in diethyl ether. A psychrometer, or wet-and-dry-bulb thermometer, consists of two thermometers, one that is dry and one that is kept moist with distilled water on a sock or wick. When the air temperature is below freezing, however, the wet-bulb is covered with a thin coating of ice and may be warmer than the dry bulb.
Relative humidity is computed from the ambient temperature as shown by the dry-bulb thermometer and the difference in temperatures as shown by the wet-bulb and dry-bulb thermometers. Relative humidity can also be determined by locating the intersection of the wet and dry-bulb temperatures on a psychrometric chart. The two thermometers coincide when the air is fully saturated, and the greater the difference the drier the air. Psychrometers are commonly used in meteorology , and in the HVAC industry for proper refrigerant charging of residential and commercial air conditioning systems.
A sling psychrometer, which uses thermometers attached to a handle or length of rope and spun in the air for about one minute, is sometimes used for field measurements, but is being replaced by more convenient electronic sensors. A whirling psychrometer uses the same principle, but the two thermometers are fitted into a device that resembles a ratchet or football rattle.
Dew point is the temperature at which a sample of moist air or any other water vapor at constant pressure reaches water vapor saturation. At this saturation temperature, further cooling results in condensation of water.
Chilled mirror dewpoint hygrometers are some of the most precise instruments commonly available. They use a chilled mirror and optoelectronic mechanism to detect condensation on the mirror's surface.
The temperature of the mirror is controlled by electronic feedback to maintain a dynamic equilibrium between evaporation and condensation, thus closely measuring the dew point temperature. An accuracy of 0. These devices need frequent cleaning, a skilled operator and periodic calibration to attain these levels of accuracy.
Even so, they are prone to heavy drifting in environments where smoke or otherwise impure air may be present. More recently, spectroscopic chilled-mirrors have been introduced. Using this method, the dewpoint is determined with spectroscopic light detection which ascertains the nature of the condensation.
This method avoids many of the pitfalls of the previous chilled-mirrors and is capable of operating drift free. For applications where cost, space, or fragility are relevant, other types of electronic sensors are used, at the price of a lower accuracy. In capacitive hygrometers, the effect of humidity on the dielectric constant of a polymer or metal oxide material is measured.
Without calibration, the accuracy is 2 to 3 times worse. Capacitive sensors are robust against effects such as condensation and temporary high temperatures. In resistive hygrometers, the change in electrical resistance of a material due to humidity is measured. The material properties also tend to depend both on humidity and temperature, which means in practice that the sensor must be combined with a temperature sensor. The accuracy and robustness against condensation vary depending on the chosen resistive material.
In thermal hygrometers, the change in thermal conductivity of air due to humidity is measured. These sensors measure absolute humidity rather than relative humidity. A Gravimetric hygrometer measures the mass of an air sample compared to an equal volume of dry air. This is considered the most accurate primary method to determine the moisture content of the air. The inconvenience of using this device means that it is usually only used to calibrate less accurate instruments, called Transfer Standards.
Aside from greenhouses and industrial spaces, hygrometers are also used in some incubators , saunas , humidors and museums. They are also used in the care of wooden musical instruments such as pianos, guitars, violins, and harps which can be damaged by improper humidity conditions.
In residential settings, hygrometers are used to assist in humidity control too low humidity can damage human skin and body, while too high humidity favors growth of mildew and dust mite. Hygrometers are also used in the coating industry because the application of paint and other coatings may be very sensitive to humidity and dew point. With a growing demand on the amount of measurements taken the psychrometer is now replaced by a dewpoint gauge known as a dewcheck.
These devices make measurements a lot faster but are often not allowed in explosive environments. Humidity measurement is among the more difficult problems in basic meteorology. According to the WMO Guide, "The achievable accuracies [for humidity determination] listed in the table refer to good quality instruments that are well operated and maintained. In practice, these are not easy to achieve.
A high-quality liquid-in-glass thermometer if handled with care should remain stable for some years. Hygrometers must be calibrated in air, which is a much less effective heat transfer medium than is water, and many types are subject to drift  so need regular recalibration.
A further difficulty is that most hygrometers sense relative humidity rather than the absolute amount of water present, but relative humidity is a function of both temperature and absolute moisture content, so small temperature variations within the air in a test chamber will translate into relative humidity variations. In a cold and humid environment, sublimation of ice may occur on the sensor head, whether it is a hair, dew cell, mirror, capacitance sensing element, or dry-bulb thermometer of an aspiration psychrometer.
The ice on the probe matches the reading to the saturation humidity with respect to ice at that temperature, i. However, a conventional hygrometer is unable to measure properly above the frost point, and the only way to go around this fundamental problem is to use a heated humidity probe. Accurate calibration of the thermometers used is fundamental to precise humidity determination by the wet-dry method.
The thermometers must be protected from radiant heat and must have a sufficiently high flow of air over the wet bulb for the most accurate results. Air is drawn through the tubes with a fan that is driven by a clockwork mechanism to ensure a consistent speed some modern versions use an electric fan with electronic speed control.
It is very challenging, particularly at low relative humidity, to obtain the maximal theoretical depression of the wet-bulb temperature; an Australian study in the late s found that liquid-in-glass wet-bulb thermometers were warmer than theory predicted even when considerable precautions were taken;  these could lead to RH value readings that are 2 to 5 percent points too high. One solution sometimes used for accurate humidity measurement when the air temperature is below freezing is to use a thermostatically-controlled electric heater to raise the temperature of outside air to above freezing.
In this arrangement, a fan draws outside air past 1 a thermometer to measure the ambient dry-bulb temperature, 2 the heating element, 3 a second thermometer to measure the dry-bulb temperature of the heated air, then finally 4 a wet-bulb thermometer.
According to the World Meteorological Organization Guide, "The principle of the heated psychrometer is that the water vapour content of an air mass does not change if it is heated. This property may be exploited to the advantage of the psychrometer by avoiding the need to maintain an ice bulb under freezing conditions. Since the humidity of the ambient air is calculated indirectly from three temperature measurements, in such a device accurate thermometer calibration is even more important than for a two-bulb configuration.