Electrometer

I want to introduct something about Intelligent IC Card Cold Water Meter. Timely Co. supplies ISO4064 intelligent IC card cold water meter LXIC -15-20, welcome to contact us for your details FEATURES ◆ Completely plastic shell, fiberglass reinforced polymerization amine (UL NO.: E154352: SGS Report NO.: CE/2006/34019) ◆ Electric stainless steel switch, Low power consuming, low pressure loss, perfect hermetization. ◆ Double dry reed switch pulse transmitting, Reliable data output, magnetic resistance. ◆ One meter, one code. ◆ Outer power supply, battery is also ok. ◆ Warn and shut down the switch when lacking water. Insert card to switch on. ◆ Warn and shut down the switch when the battery is out of service. ◆ Clock electro-circuit inside to switch on and shut down the switch regularly, preventing from valve blocked up. ◆ Support the ladder water price and southern seasonal water price. ◆ LCD screen, low power consuming. ◆ Identifiable remaining water quantit An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical hand-made mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges.Contents1 Simple charge indicating device 2 Modern electrometers 2.1 Vibrating reed electrometers 2.2 Valve electrometers 2.3 Solid-state electrometers 3 Experiments with an electroscope 4 Patents 5 See also 6 External links // Simple charge indicating deviceGold-leaf electroscopeThe gold-leaf electroscope was one of the first sensitive instruments used to indicate electric charge. It is still used for science demonstrations but has been superseded in most applications by electronic measuring instruments. The instrument consists of two thin leaves of gold foil suspended from an electrode. When the electrode is charged by induction or by contact, the leaves acquire similar electric charges and repel each other due to the Coulomb force. Their separation is a direct indication of the net charge stored on them. The leaves may be enclosed in a glass envelope to protect them from draughts, and the envelope may be evacuated to minimize charge leakage. A further cause of charge leakage is ionizing radiation, so to prevent this, the electrometer must be surrounded by lead shielding. It should be noted that this type of electroscope usually acts as an indicator and not a measuring device, although it can be calibrated. The Braun electroscope replaced the gold-leaf electroscope for more accurate measurements.The most common radiation measurement device, and widely used in the nuclear industry, the Quartz Fibre Electrometer (or QFE) personal dosimeter, is actually a ruggedized, calibrated electroscope. It uses the leakage effect mentioned above to detect ionizing radiation.The instrument was developed in the 1700s by several researchers, among them Abraham Bennet and Alessandro Volta.Modern electrometersIn modern parlance, an electrometer is a highly sensitive electronic voltmeter whose input impedance is so high that the current flowing into it can be considered, for practical purposes, to be zero. They are of use in nuclear physics as they are able to measure the tiny charges left in matter by the passage of ionizing radiation. The most common use for modern electrometers is probably the measurement of radiation with ionization chambers, in instruments such as geiger counters.Vibrating reed electrometersVibrating reed electrometers use a variable capacitor formed between a moving electrode (in the form of a vibrating reed) and a fixed input electrode. As the distance between the two electrodes varied, the capacitance also varies and electric charge is forced in and out of the capacitor. The ac signal produced by the flow of this charge is amplified and used as an analogue for the dc voltage applied to the capacitor. The input resistance of the electrometer is determined solely by the leakage resistance of the capacitor (although its ac input impedance is clearly less than infinity).For convenience of use, the vibrating reed assembly is often attached by a cable to the rest of the electrometer. This allows for a relatively small unit to be located near the charge to be measured while the much larger reed-driver and amplifier unit can be located wherever it is convenient for the operator.Valve electrometersValve type electrometers use an unbiased vacuum tube with a very high gain (transconductance) and input resistance. The input current is allowed to flow into the high impedance grid, and the voltage so generated is vastly amplified in the anode (plate) circuit. The best examples of these valves have leakage currents as low as a few femtoamperes (10-15 amperes). This type of valve can be ruined by handling with ungloved hands as the salts left on the glass envelope can provide leakage paths for these tiny currents.Solid-state electrometersThe most modern electrometers consist of a solid state amplifier circuit using FETs, connections for external measurement devices, and also possibly a display, data-logging connections, and/or a high-voltage supply. The amplifier magnifies small currents so that they are more easily measured. The external connections are usually of a co-axial or tri-axial design, and allow attachment of diodes or ionization chambers for radiation measurement. The display or data-logging connections allow the user to see the data or record it for later...(and so on) To get More information , you can visit some products about water temperature indicator, Meter Air Flow, . The Intelligent IC Card Cold Water Meter products should be show more here!