Technical Specifications INPUT CHARACTERISTICS Input Current: DC NMR: 1k Unbalanced CMR: < 100 pA. > 60dB at 50/60Hz. > 120dB at DC/50Hz/60Hz, DC ranges; > 60dB at DC/50Hz/60Hz, AC ranges. AC AMPS (True RMS) Range ACCURACY Accuracies apply for 1 year 18oC to 26oC. Temperature coefficient outside these limits is <0⋅1 x quoted range accuracy per oC. Warm-up time to rated accuracy is 1 hour. DC VOLTS Range Accuracy(±) 200mV 2V 20V 200V 1000V 0⋅017% + 3d 0⋅012% + 3d 0⋅019% + 3d 0⋅019% + 3d 0⋅019% + 3d Input Impedance Max Input 10MΩ or >1GΩ 1kV DC or AC Peak any range (Hi Z mode) 10MΩ Range Accuracy(±) Max. Measuring Current Max. Input 200 2k 20k 200k 2M 20M 0⋅025% + 4d 0⋅019% + 3d 0⋅019% + 3d 0⋅019% + 3d 0⋅022% + 3d 0⋅07% + 3d 1⋅5mA 1⋅5mA 0⋅4mA 40µA 4µA 400nA 300V DC or RMS continuous any Ohms input any range Accuracy(±) 45Hz - 5kHz 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 5kHz - 10kHz 0⋅2% + 250d 0⋅2% + 250d 0⋅2% + 250d 0⋅2% + 250d - 10kHz-20kHz 20kHz-50kHz 3% + 500d 0⋅5% + 300d 3% + 1500d 0⋅5% + 300d 2% + 1000d 0⋅5% + 500d - Overrange: Overflow: Annunciators: 200µA 2mA 20mA 200mA 10A 0⋅08% + 12d 300 mV max 0⋅08% + 12d 0⋅08% + 12d 0⋅08% + 12d 0⋅08% + 12d 650mV max 0⋅12% + 12d <2000mA >2000mA Voltage Burden 1A, 300V fuse protected 650mV max 10A, 300V fuse protected THURLBY THANDAR INSTRUMENTS 1906 13mm LED, 8 digit. Selectable 5½ digit or 4½ digit. 3 readings/sec (5½ digit). 10 readings/sec (4½ digit). Displays OL if input too great for range. Displays OFLO if calculated result overflows display. LEDs for range, function and program modes. COMPUTING FUNCTIONS Null: Digital Filter: Min/Max: Data Logger: Operates over full range; values can be stored for every function. 10 options, including optimised default values for each range and function. Reading is held when stable. Displays % deviation from entered reference value. Displays measurement in dB relative to 1V, 1mA, 1kΩ or user entered value, or in dBm. Linear scaling of results, with offset. Reading displayed with H, L, or P (pass) with respect to user-defined high and low limits. Minimum and maximum reading stored. Manual or automatic storage of 100 measurements, Storage interval 1s to 9999s. INTERFACES RS232: GPIB (Optional): AC Input: DC AMPS Accuracy(±) 300mV max Baud rates 300, 1200 or 9600. Complies fully with the ARC (Addressable RS232 Chain) interface standard. Address selectable from the front panel. Fully complies with IEEE-488.1 and IEEE-488.2 POWER REQUIREMENTS Additional error at crest factor=3 typically 0⋅7% Input impedance 1MΩ / <100 pF any range. Max input 750V rms, 1kV peak, any range. Range Max Input DISPLAY Ax+B: Limits: AC VOLTS (True RMS) 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅4% + 100d Voltage Burden Additional error at crest factor=3 typically 0⋅7%. Touch & Hold: % DEV: dB: Max open circuit voltage 3⋅5V. Diode Test on 2k range. Audible continuity check available on all ranges. 200mV 2V 20V 200V 750V <2000mA >2000mA Display Type: Scale Length: Reading Rate: RESISTANCE (OHMS) Range 200µA 2mA 20mA 200mA 10A Accuracy(±) 45 Hz - 1 kHz Max. Input 1A, 300V fuse protected 10A, 300V fuse protected Consumption: 110/120 Volts AC nominal 50/60Hz or 220/240 Volts AC nominal 50/60Hz by rear panel adjustment. The instrument will operate safely and meet specification within normal AC supply variations, viz. 99-132 Volts AC and 198-264 Volts AC respectively. 25VA max. GENERAL Operating Range: Storage Range: Size: Weight: +5oC to +40oC, 20% to 80% RH -40oC to +60oC 260(W) x 88(H) x 235(D)mm, excl. handle and feet 2⋅2kg. Thurlby Thandar Instruments Ltd. operates a policy of continuous development and reserves the right to alter specifications without prior notice. 51/2 digit computing multimeter Full autoranging, True RMS, RS-232 & GPIB interfaces Designed and built in the U.K. by: Thurlby Thandar Instruments Limited Glebe Road, Huntingdon. Cambs. PE18 7DX England Tel: (0)1480 412451, Fax: (0)1480 450409 82100-0047 built-in computing & data logging 5½ digit performance at a 4½ digit price higher resolution, accuracy & functionality Greater resolution and accuracy 51/2 The 1906 is a true digit meter with a scale length of ± 210,000 counts. This gives it not just superior resolution relative to 41/2 digit meters, but much higher effective accuracy as well. 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. 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 diagram shows how the effective accuracy varies with reading after taking into account the fixed errors. Over a range of voltages, the 1906 is around four times more accurate than a typical 41/2 digit meter. The 1906 stores its calibration constants in permanent memory (EEPROM). Consequently it can be recalibrated without ever opening the case. full bus programmability Storage of front-panel set-ups Single key convenience functions for ease of use Linear scaling with offset (Ax+b) 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. This facility is particularly valuable when similar tests need to be repeated at intervals. 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. 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. Full protection for the instrument and the user 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. 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 display then shows a code of H (high), L (low) or P (pass) at the end of the display. 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. With a maximum resolution of 1µV, 1mΩ and 1nA, the 1906 is ten times more sensitive than a 41/2 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. 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. Industry standard 10MΩ input impedance applies to all dc voltage ranges, but the lowest two can alternatively be selected at greater than 1000MΩ impedance to eliminate errors when measuring high impedance circuitry. 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. The resistance function also provides selectable audible continuity as well as diode test capabilities. This function enables the reading to be tested against high and low limits set by the user. Percentage deviation (∆%) Greater sensitivity and higher input impedance 4 terminal Ohms for improved stability Limits comparison ● ● ● ● ● ● ● ● 5 1/2 digit scale length (±210,000 counts) 0.012% basic one year accuracy 1uV, 1m Ω and 1nA resolution, 4 terminal Ohms Full automatic or manual ranging True RMS ac functions, wide ac bandwidth Full set of current ranges from 200uA to 10A Wide range of computing and data logger functions Fully programmable by RS-232 or GPIB interfaces 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. 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. 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). The RS-232 interface, which is fitted as standard, is compatible with the TTi ARC system. The ARC system (Addressable RS232 Chain) enables up to 32 instruments to be “daisy-chained” together and to be individually addressed and controlled using a single RS232 port of a PC. Compatible with IEEE-488.2 The GPIB interface is an option. When installed, a rear panel switch allows the user to choose between RS232 or GPIB control. The GPIB interface conforms fully with both IEEE-488.1 and IEEE-488.2. The .2 standard contains many enhancements which are particularly important when programming systems incorporating a number of instruments. built-in computing & data logging 5½ digit performance at a 4½ digit price higher resolution, accuracy & functionality Greater resolution and accuracy 51/2 The 1906 is a true digit meter with a scale length of ± 210,000 counts. This gives it not just superior resolution relative to 41/2 digit meters, but much higher effective accuracy as well. 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. 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 diagram shows how the effective accuracy varies with reading after taking into account the fixed errors. Over a range of voltages, the 1906 is around four times more accurate than a typical 41/2 digit meter. The 1906 stores its calibration constants in permanent memory (EEPROM). Consequently it can be recalibrated without ever opening the case. full bus programmability Storage of front-panel set-ups Single key convenience functions for ease of use Linear scaling with offset (Ax+b) 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. This facility is particularly valuable when similar tests need to be repeated at intervals. 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. 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. Full protection for the instrument and the user 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. 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 display then shows a code of H (high), L (low) or P (pass) at the end of the display. 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. With a maximum resolution of 1µV, 1mΩ and 1nA, the 1906 is ten times more sensitive than a 41/2 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. 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. Industry standard 10MΩ input impedance applies to all dc voltage ranges, but the lowest two can alternatively be selected at greater than 1000MΩ impedance to eliminate errors when measuring high impedance circuitry. 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. The resistance function also provides selectable audible continuity as well as diode test capabilities. This function enables the reading to be tested against high and low limits set by the user. Percentage deviation (∆%) Greater sensitivity and higher input impedance 4 terminal Ohms for improved stability Limits comparison ● ● ● ● ● ● ● ● 5 1/2 digit scale length (±210,000 counts) 0.012% basic one year accuracy 1uV, 1m Ω and 1nA resolution, 4 terminal Ohms Full automatic or manual ranging True RMS ac functions, wide ac bandwidth Full set of current ranges from 200uA to 10A Wide range of computing and data logger functions Fully programmable by RS-232 or GPIB interfaces 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. 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. 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). The RS-232 interface, which is fitted as standard, is compatible with the TTi ARC system. The ARC system (Addressable RS232 Chain) enables up to 32 instruments to be “daisy-chained” together and to be individually addressed and controlled using a single RS232 port of a PC. Compatible with IEEE-488.2 The GPIB interface is an option. When installed, a rear panel switch allows the user to choose between RS232 or GPIB control. The GPIB interface conforms fully with both IEEE-488.1 and IEEE-488.2. The .2 standard contains many enhancements which are particularly important when programming systems incorporating a number of instruments. Technical Specifications INPUT CHARACTERISTICS Input Current: DC NMR: 1k Unbalanced CMR: < 100 pA. > 60dB at 50/60Hz. > 120dB at DC/50Hz/60Hz, DC ranges; > 60dB at DC/50Hz/60Hz, AC ranges. AC AMPS (True RMS) Range ACCURACY Accuracies apply for 1 year 18oC to 26oC. Temperature coefficient outside these limits is <0⋅1 x quoted range accuracy per oC. Warm-up time to rated accuracy is 1 hour. DC VOLTS Range Accuracy(±) 200mV 2V 20V 200V 1000V 0⋅017% + 3d 0⋅012% + 3d 0⋅019% + 3d 0⋅019% + 3d 0⋅019% + 3d Input Impedance Max Input 10MΩ or >1GΩ 1kV DC or AC Peak any range (Hi Z mode) 10MΩ Range Accuracy(±) Max. Measuring Current Max. Input 200 2k 20k 200k 2M 20M 0⋅025% + 4d 0⋅019% + 3d 0⋅019% + 3d 0⋅019% + 3d 0⋅022% + 3d 0⋅07% + 3d 1⋅5mA 1⋅5mA 0⋅4mA 40µA 4µA 400nA 300V DC or RMS continuous any Ohms input any range Accuracy(±) 45Hz - 5kHz 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 0⋅2% + 150d 5kHz - 10kHz 0⋅2% + 250d 0⋅2% + 250d 0⋅2% + 250d 0⋅2% + 250d - 10kHz-20kHz 20kHz-50kHz 3% + 500d 0⋅5% + 300d 3% + 1500d 0⋅5% + 300d 2% + 1000d 0⋅5% + 500d - Overrange: Overflow: Annunciators: 200µA 2mA 20mA 200mA 10A 0⋅08% + 12d 300 mV max 0⋅08% + 12d 0⋅08% + 12d 0⋅08% + 12d 0⋅08% + 12d 650mV max 0⋅12% + 12d <2000mA >2000mA Voltage Burden 1A, 300V fuse protected 650mV max 10A, 300V fuse protected THURLBY THANDAR INSTRUMENTS 1906 13mm LED, 8 digit. Selectable 5½ digit or 4½ digit. 3 readings/sec (5½ digit). 10 readings/sec (4½ digit). Displays OL if input too great for range. Displays OFLO if calculated result overflows display. LEDs for range, function and program modes. COMPUTING FUNCTIONS Null: Digital Filter: Min/Max: Data Logger: Operates over full range; values can be stored for every function. 10 options, including optimised default values for each range and function. Reading is held when stable. Displays % deviation from entered reference value. Displays measurement in dB relative to 1V, 1mA, 1kΩ or user entered value, or in dBm. Linear scaling of results, with offset. Reading displayed with H, L, or P (pass) with respect to user-defined high and low limits. Minimum and maximum reading stored. Manual or automatic storage of 100 measurements, Storage interval 1s to 9999s. INTERFACES RS232: GPIB (Optional): AC Input: DC AMPS Accuracy(±) 300mV max Baud rates 300, 1200 or 9600. Complies fully with the ARC (Addressable RS232 Chain) interface standard. Address selectable from the front panel. Fully complies with IEEE-488.1 and IEEE-488.2 POWER REQUIREMENTS Additional error at crest factor=3 typically 0⋅7% Input impedance 1MΩ / <100 pF any range. Max input 750V rms, 1kV peak, any range. Range Max Input DISPLAY Ax+B: Limits: AC VOLTS (True RMS) 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅37% + 100d 0⋅4% + 100d Voltage Burden Additional error at crest factor=3 typically 0⋅7%. Touch & Hold: % DEV: dB: Max open circuit voltage 3⋅5V. Diode Test on 2k range. Audible continuity check available on all ranges. 200mV 2V 20V 200V 750V <2000mA >2000mA Display Type: Scale Length: Reading Rate: RESISTANCE (OHMS) Range 200µA 2mA 20mA 200mA 10A Accuracy(±) 45 Hz - 1 kHz Max. Input 1A, 300V fuse protected 10A, 300V fuse protected Consumption: 110/120 Volts AC nominal 50/60Hz or 220/240 Volts AC nominal 50/60Hz by rear panel adjustment. The instrument will operate safely and meet specification within normal AC supply variations, viz. 99-132 Volts AC and 198-264 Volts AC respectively. 25VA max. GENERAL Operating Range: Storage Range: Size: Weight: +5oC to +40oC, 20% to 80% RH -40oC to +60oC 260(W) x 88(H) x 235(D)mm, excl. handle and feet 2⋅2kg. Thurlby Thandar Instruments Ltd. operates a policy of continuous development and reserves the right to alter specifications without prior notice. 51/2 digit computing multimeter Full autoranging, True RMS, RS-232 & GPIB interfaces Designed and built in the U.K. by: Thurlby Thandar Instruments Limited Glebe Road, Huntingdon. Cambs. PE18 7DX England Tel: (0)1480 412451, Fax: (0)1480 450409 82100-0047