Help with Mechanical Pressure Gauges specifications:
Type
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| Absolute | Absolute pressure is relative to a perfect vacuum. | ||
| Differential | Differential pressure is the difference between two input pressures. | ||
| Gauge | Gauge pressure is the pressure measured above the local atmospheric pressure. It is the most common pressure measurement. | ||
| Compound | Devices can display both positive and negative (vacuum) pressures. | ||
| Sealed | Sealed gauge pressure is relative to one atmosphere at sea level (14.7 psi) regardless of local atmospheric pressure. | ||
| Vacuum | Vacuum pressure is lower than atmospheric pressure. | ||
| Other | Other unlisted, specialized, or proprietary measurement types. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Liquid Filled | Liquid filled gauges are filled with a liquid such as glycerin or silicone oil to protect the gauge from the harmful effects of vibration and pulsation. | ||
| Search Logic: | "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice. | ||
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Specifications
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| Working Pressure Range | The maximum allowable pressure at which a system or piece of equipment is designed to operate safely. The extremes of this range should be determined in accordance with the expected pressure range the device must operate within. It is common practice that this value should not exceed 75% of the devices maximum rated range. For example: if the device has a maximum rated range of 100 psi then the working range should not exceed 75 psi. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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| Dial Diameter: | The diameter of the gauge. The dial size is usually determined by the readability requirements; larger for remote reading and smaller where the gauge is close to the operator. Generally, a requirement for higher accuracy dictates a larger dial size for display of readable small pressure scale increments. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Pressure Connection Size | Size of the pressure connection. 1/4" NPT would be represented as .25 inches. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Accuracy | The difference (error) between the true value and the indication expressed as percent of the span. It includes the combined effects of method, observer, apparatus and environment. ASME B40.1 and DIN accuracy grades are frequently used: Grade 4A (0.1% Full Scale) Grade 3A (0.25% Full Scale) Grade 2A (0.5% Full Scale) Grade 1A (1% Full Scale) Grade A (1% middle half, 2% first and last quarters) Grade B (2% middle half, 3% first and last quarters) Grade C (3% middle half, 4% first and last quarters) Grade D (5% Full Scale) Measurement Accuracy (% of Full Scale). In cases where the accuracy differs between middle span and the first and last quarters of the scale, the largest % error is reported. | ||
| Search Logic: | All matching products will have a value less than or equal to the specified value. | ||
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| Vacuum Range | Vacuum range is the span of pressures from the lowest vacuum pressure to the highest vacuum pressure (e.g., from 0 to 30 inches of mercury VAC). | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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| Operating Temperature | The full-required range of ambient operating temperature. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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Mount / Connection Location
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| Your choices are... | |||
| Bottom | Port is located at the bottom of the gauge. | ||
| Center Back | Port is located at the center back. | ||
| Lower Back | Port is located at the on the back lower. | ||
| Flange | Mounted by a flange around the face or back of the gauge. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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Scale Specifications
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| Scale Type: | Search Logic: An item matches if it has ANY of the attributes you select. Selecting none (or all) of the options will match everything. | ||
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| Single Scale | Measurement scale displays pressure in only one set of units on the dial face. | ||
| Dual Scale | Measurement scale displays pressure in two sets of units on the same dial face. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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| Scale Units: | Scale Units: Select the desired pressure measurement units. Common units are given. Special units and compound ranges are usually available. | ||
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| psi | Pounds per square inch: psi, PSI, lb./in^2, or lb./sq. in. | ||
| kPa | kilo Pascal’s - standard atmospheric pressure is 101,325 Pa or 101.325 kPa | ||
| bar | A unit of measure of atmospheric pressure. One bar is equal to 0.987 atmospheres | ||
| inches of Hg | One inch of mercury is equivalent to 33.86 millibars. | ||
| cm of Hg | A metric measure of pressure. | ||
| feet of H2O | The pressure equivalent for 1 foot of water is .0295 atm | ||
| kg/cm2 | The pressure equivalent for 1 kg/cm2 is .9678 atm | ||
| oz./in2 | The pressure equivalent for 1 atmosphere of pressure is approx. 235 oz. / in2 | ||
| inches of H2O | The pressure equivalent for 1 inch of water is .00245 atm | ||
| Other | Other unlisted or specialized scale units. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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Technology Used
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| Sensor Technology: | |||
| Your choices are... | |||
| Mechanical Deflection | An elastic or flexible element mechanically deflects with a change in pressure, for example a diaphragm, Bourdon tube, or bellows. | ||
| Piston | A sealed piston / cylinder measures changes in pressure. | ||
| Strain Gauge | Strain gages (strain-sensitive variable resistors) are bonded to parts of the structure that deform as the pressure changes. These strain gages are typically used as elements in a Wheatstone bridge circuit, which is used to make the measurement. | ||
| Semiconductor Piezoresistive | Piezoresistive sensors are based on semiconductor technology. The change in resistance is not only because of a change in the length and width (as it is with strain gage) but because of a shift of electrical charges within the resistor. These are very sensitive devices. | ||
| Piezoelectric | Piezoelectric pressure sensors measure dynamic and quasi-static pressures. The common modes of operation are charge mode, which generates a high-impedance charge output; and voltage mode, which uses an amplifier to convert the high-impedance charge into a low-impedance output voltage. | ||
| Thin Film | An extremely thin layer of material is deposited on a substrate by sputtering, chemical vapor deposition, or other technique. This technology incorporates a compact design with good temperature stability. There are a variety of materials used in thin film technology, such as titanium nitride and polysilicon. | ||
| MEMS | Microelectromechanical systems (MEMS) are typically manufactured by silicon surface micromachining. | ||
| Variable Capacitance | The capacitance change results from the movement of a diaphragm element. The deflection of the diaphragm causes a change in capacitance that is detected by a bridge circuit. | ||
| Vibrating Element | These devices use a vibrating element technology, such as silicon resonance. | ||
| Other | Other unlisted, specialized, or proprietary technologies. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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Media
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| Liquid | The device measures the pressure of liquids. | ||
| Gas | The device measures the pressure of gases. | ||
| Hazardous | The device is rated by the manufacturer for hazardous duty. | ||
| Other | Other unlisted, specialized, or proprietary materials to measure. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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