|
“Tomorrow’s Instruments Today” — “For Good Measure” ® |
|
A Leading South African Test and Measurement Instruments Supplier |
|
“For Good Measure”® |
|
TMI, Established—1982 |
|
Test and Measurement Instruments C.C. |
|
Test our Service and Measure with our Instruments. |
|
CK 85/07464/23 |
|
Please contact us by phone, fax, email or visit us at the details given above. We look forward to hearing from you. |
|
|
|
Product List |
|
All brands, trade names, trade marks, and logos are the property of their respective owners. |
|
Brand Names |
|
T + M ® |
|
English, Afrikaans and Portuguese Speaking No Credit Card Payments yet. |
|
Ph: +27 (011) 683 4365 Fax: +27 (011) 683 4461 E-mail: t.m.i@iafrica.com
Physical Address: 1st Floor, TMI House, 37 Garden St, Cnr 160 Bellavista Rd, Turfclub, Johannesburg, 2135 SOUTH AFRICA
Postal Address: P.O. Box 1416, Southdale, Johannesburg, 2135, SOUTH AFRICA
|
|
T.M.I. |
|
This Month’s Special |
|
Excess Stock to be cleared while stocks last. > Click for More... |
|
Thermography—Thermal Imager— Infrared Camera. FLIR i3 — Smallest , Lightest, most affordable camera “point-shoot-detect”. Introductory Nett Price of R 11 990.00 + VAT while stocks last. |
|
Milliohm Meters |
|
Milliohm Meters |
|
Part No: MO-2001 |
|
200m/2000m/20/200/2000/20,000 ohm, 4 terminal input high accuracy, handheld, portable |
|
Part No: MO-2002 |
|
Bench Type, 0.01mohm to 20Kohm(7 ranges) 4 terminal input with LED display. |
|
Lutron |
|
Lutron |
|
Notes on Milliohm Meters. Milliohm meters are capable of measuring very small resistances. Devices which use a four-wire Kelvin probe system pass a test current through the probe so that the voltage is sensed by the center pin. This test method eliminates contact resistance and minimizes the possibility of errors caused by the resistance of the leads. By definition, resistance or impedance is a measure of the degree to which a material or device opposes the flow of current. This value is equal to the voltage drop across the element divided by the current through the element. As their name suggests, milliohm meters measure resistance in milliohms, a unit of measure which equals 1/1000 of an ohm. Milliohm meters carry specifications for bandwidth, sampling rate, maximum channels, and operating temperature, as well as display type and display digits. Bandwidth is the frequency range for AC current or voltage to be measured. Sampling rate is the frequency that a digital meter tests an analog signal and converts it to a digital value. Maximum channels are the total number of channels for the device. Operating temperature is the full required range of temperatures over which milliohm meters operate. There are two choices for display type: analog and digital. Analog devices usually display values with a needle. Digital devices have an electronic display. For milliohm meters, the number of display digits ranges from 3 to 7 or more. Devices that can display a half-digit are also available. Milliohm meters are available in several different form factors. Benchtop meters are designed to sit atop a bench or table. Free-standing devices have a full case or cabinet and an integral interface. Milliohm meters that function as clamp meters measure current through wires that are connected to the circuit. Rack-mounted devices include hardware such as rail guides, flanges and tabs. Handheld milliohm meters are relatively lightweight and can be operated while held in the hand. Devices with a computer-board form factor are printed circuit boards (PCBs) that plug into motherboards or backplanes. Milliohm meters with other form factors are also available. Standards, options and features are important parameters to consider when specifying milliohm meters. Some products have an adjustable sampling rate, alarm lights, auto-ranging capabilities, and integral application software. Others feature data acquisition, data storage or logging, decibel reading, and external triggering capabilities. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated. Mirrored scales facilitate readings to a given accuracy and help operators avoid parallax errors. Range switches can be used to select the range of units to measure. Milliohm meters with overload protection, filters, scaling functions, and temperature compensation are also available.
|
|
On Digital Resistance Meters. Digital resistance meters are instruments that measure electrical resistance. They use solid-state components and display values digitally. Resistance, which is measured in ohms, is the opposition to the flow of electric current of a conductor. Typically, digital resistance meters are powered by an internal battery that applies a small voltage to the circuit being tested. The positive lead is connected to the circuits positive side and the negative lead is connected to the circuits ground. The current is then measured and the resistance calculated. Zero resistance indicates a short. Infinite resistance indicates an open. Often, resistance readings that exceed product specifications are caused by a faulty component or problems such as burnt contacts, corroded terminals, or loose connections. To maintain accuracy, digital resistance meters require regular calibration that consists of connecting the two leads together and zeroing the meter with the adjustment knob. Digital resistance meters typically display between three and seven digits along with a leading number such as 0 or 1. Four-wire systems minimize voltage drops in the test leads and record highly accurate measurements. Some digital resistance meters are used to monitor devices such as resistance temperature detectors (RTDs) or thermocouples. Others are used to monitor electronic components such as transistors or diodes. Benchtop, rack mounted, and handheld devices are commonly available. Battery powered units do not require plug-in power. Digital resistance meters with audibility continuity beep when the probes touch. Devices with analog bar graph capabilities display status readings such as battery power, signal level, and continuity. Digital resistance meters interface to computers and include integral monitoring software for applications such as data acquisition. Programmable digital resistance meters allow users to set values that trigger monitoring routines. Data storage, logging, and removable data storage devices are often available. Some digital resistance meters allow users to adjust the sampling rate or provide internal memory. Others include an auto-ranging feature that automatically adjusts the measurement range. Output options include general-purpose interface bus (GPIB), binary coded decimal (BCD), and digital-to-analog (DA). RS232 is a standard communication protocol for serial ports. IEEE 488 is a standard communication protocol for parallel ports. |
|
Part No: MO-2013 |
|
Milliohm Meter, Bench Type, 0.001mohm to 20Kohm (7 ranges) 4 terminal input with LED display. RS232/USB Computer Interface, Large Backlit LCD Readout. |
|
Lutron |
|
Copyright © 2009—2012 Test and Measurement Instruments C.C. | All rights reserved Milliohm Meters |