Precision Measurement Instruments from TTi - Thurlby Thandar Instruments

Greater resolution and accuracy
The 1906 is a true 5.5 digit meter with a scale length of ± 210,000 counts. This gives it not just superior resolution relative to 4.5 digit meters, but much higher effective accuracy as well.
Greater sensitivity and higher input impedance
With a maximum resolution of 1mV, 1mW and 1nA, the 1906 is ten times more sensitive than a 4.5 digit meter.
This extra senstivity enables accurate measurements to be made in areas previously impossible such as thermocouple junctions, switch contact resistance or capacitor leakages.
4 terminal Ohms for improved stability
Resistance measurements can be made in either 2 terminal or 4 terminal mode. High impedance sensing ensures that the meter switches automatically between modes. For low resistance measurements, 4 terminal mode offers much higher accuracy and repeatability.
True RMS ac functions
The 1906 provides True RMS ac response which gives accurate measurements regardless of the waveform shape. The wide bandwidth voltage attenuator provides high accuracy within the audio band and gives extended response to avoid distortion when measuring switching waveforms.
Full bus control via RS-232 or GPIB
The 1906 is designed for complete bus control. Every function of the instrument can be controlled using either the RS-232 interface or the GPIB interface (optional).
Wide range of Smart functions
The 1906 offers computing and datalogging functions as standard: dBs, Ax+b, Limits, % deviation, Min-Max, and a 100 reading Data-logger.
Auto or manual ranging
The 1906 offers fully automatic ranging on all functions including current. Alternatively any range can be selected and held manually.
Closed case calibration
The 1906 stores its calibration constants in permanent memory. Consequently it can be recalibrated without ever opening the case.
Storage of front-panel set-ups
The 1906 can store up to six front panel set-ups in non-volatile memory. In addition to the range and function each set-up defines the active computing or logging functions along with their parameters.
Single key convenience functions for ease of use
Press the “null” key and the present displayed reading is stored and subtracted from all future readings. This powerful feature has a host of uses such as removing test lead resistance, observing deviation levels, or measuring relative to alternative voltage points using a fixed ground lead connection.
Full protection for the instrument and the user
The 1906 incorporates extensive protection against damage from accidental overloads on all ranges including 10 Amps.
In addition the 1906 meets the stringent safety requirements of IEC348 and IEC1010-1 for measurements up to 1kV.

Touch and Hold
The touch and hold function is invaluable when taking measurements in awkward situations where it may be difficult to see the multimeter display. With touch and hold selected, the display is automatically frozen every time a stable reading is achieved. A further press of the T/HOLD key un-freezes the display.
Digital filtering for better noise performance
The 1906 uses non-linear digital filtering which is highly effective in eliminating unwanted noise, but responds rapidly to a change in the reading. When working with very noisy or unstable measurements, the characteristics of the digital filter can be adjusted to suit the application.
Linear scaling with offset (Ax+b)
This function enables a reading to be multiplied by a scale factor (A) and for an offset (b) to be added or subtracted. This means, for example, that the electrical output of a transducer can be scaled to give a direct readout of the physical parameter e.g. temperature or weight. It is particularly useful with 4-20mA current loops.
Limits comparison
This function enables the reading to be tested against high and low limits set by the user. The display then shows a code of H (high), L (low) or P (pass) at the end of the display.
Percentage deviation (D%)
This function enables the meter to display the percentage amount by which the reading differs from a nominal value chosen by the user. It is invaluable for measuring tolerance or stability.
Min-Max storage
The Min-Max function stores the highest and lowest values of a set of readings. This facility has many uses such as checking for power supply glitches, recording peak temperature excursions and avoiding “missed” readings when using the Logger function.
Logarithmic measurements (dB)
This function allows measurements to be displayed in the form 20log10X. Built-in zero reference scaling enables voltages to be displayed in dBV or dBm relative to any required impedance. Using the null key allows gains and losses to be measured directly.
Automatic data logging
The 1906 can store up to 100 readings at any required time interval from 1 reading per second up to 1 reading every 3 hours.
A simple recall sequence allows the readings to be scrolled onto the display whenever required. Alternatively results can be downloaded using the RS232 or GPIB interfaces. As a result, tedious time related measurement sequences can be handled automatically without disrupting your work.
Manual storage of readings is also available eliminating the need for paper and pencil when making a series of measurements. Storage can also be triggered from the RS-232 or GPIB interfaces.