TTi Precision Measurement Instruments

  1705  - Description and Specifications

1705 - Dual Measurement LCD Bench Multimeter

  4¼ digit dual LCD
  Dual 12,000 count, auto/manual ranging
  Accuracy and resolution: 0.04%, 10µV, 10mW
  Dual displays & ‘dual measurement’ technology
  True RMS ac functions, Frequ., Capacitance
  Wide range of computing functions e.g. Ax + B
  RS232 interface standard, GPIB optional
  Mains and battery operation as standard

 

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High resolution & accuracy

The 1705 is a 4¼ digit meter with a scale length of 12,000 counts and a resolution of 10µV, 10mOhms and 0.1µA. Combined with a high basic dcV accuracy of 0.04%, it provides measurements that are an order of magnitude better than most hand-held DMMs.

Dual display system

The 1705 has both a main display and a secondary display. The two displays can be used for a variety of purposes:
To show the selected range in addition to the measurement units (e.g. 100mA dc).
To display a measurement in two different units - (e.g. ac volts and dBm).
To display the result of a calculated function - (e.g. Ws value and % deviation).
To measure and display two parameters of one signal - (e.g. ac and dc volts).
To measure and display two different signals - (e.g. ac volts and dc current).

Wide bandwidth ac with true RMS

The 1705 provides True RMS ac response which gives accurate measurements regardless of the waveform shape. The wide bandwidth attenuator provides high accuracy within the audio band and gives extended response to avoid errors when measuring switching waveforms.
Measurements are normally ac coupled but, when required, the true RMS value of the ac plus dc components can be shown.

Frequency & capacitance

The 1705 offers high accuracy frequency measurement (better than 0.01%) from 10Hz to 120kHz. It uses a reciprocal counting technique to give up to 0.01Hz resolution at 10 readings per second.
The 1705 also incorporates capacitance measurement in four ranges up to 120µF.

Wide range of Smart functions

The 1705 offers computing and datalogging functions as standard: dBs, Ax+b, Limits, % deviation, Min-Max, Power, and a 100 reading Data-logger.

 

Full bus control via RS-232 or GPIB

The 1705 has an RS-232 interface as standard which can be used for remote control and read-back of measurements.  A GPIB interface is available as an option.

Dual measurement

The 1705 can measure and display two signals simultaneously.  These can be two parameters of one signal (e.g. ac volts & dc volts) or two signals applied to different sockets (e.g. ac volts & ac current).

 Examples 

Main
display

Secondary display

Signal inputs

dc Volts

ac Volts

1

dc Volts

ac Amps

2

ac Volts

Frequency

1

ac Volts

dc Amps

2

dc Amps

ac Amps

1

ac Amps

ac Volts

2

 Dual displays
The 1705 has a number of powerful built-in functions designed to make life easier for the user.  Most of these functions make use of the dual displays to provide extra information.

 Examples 

Function

Main display

Secondary display

dB

dBm

ac Volts

Null

nulled value

raw value

Power

ac Volts

V2/R

VA

dc Amps

Volts x Amps

Limits

Resistance

Hi/Lo/Pass

Ax + B

dc Volts

Weight

 

ACCURACY (Main Measurement Functions)

Accuracies apply for 1 year, 19oC to 25oC.  Temperature coefficient outside these limits is <0.1 x quoted range accuracy per oC

DC Volts

Range

Accuracy

Resolution

Notes

100mV

0.06% ± 3 dig.

10µV

Input impedance 10M
Max. input 1kV DC or AC pk
NMR: >60dB @ 50/60Hz
CMR: >90dB @ DC/50Hz/60Hz

1V

0.04% ± 2 dig.

100µV

10V

0.06% ± 2 dig.

1mV

100V

0.06% ± 2 dig.

10mV

1000V

0.06% ± 2 dig.

100mV

AC Volts (True RMS)

Range

Accuracy

Resolution

 

45Hz - 10kHz

10kHz - 20kHz

20kHz - 50kHz

 

100mV

0.2% ± 20 dig.

1% ± 20 dig.

N/A

10µV

1V

0.2% ± 20 dig.

1% ± 50 dig.

100µV

10V

1% ± 80 dig.

1mV

100V

1% ± 80 dig.

10mV

750V

N/A

100mV

1V, 10V, 100V ranges are <1dB down at 100kHz.  AC accuracies apply above 1,000 counts.  
Additional error at crest factor = 3 is typically 0.2%. Input impedance = 1M nominal.  
Max. input = 750V rms, 1kV pk. 1k unbalanced CMR = >60dB at DC/50Hz/60Hz.

Resistance (Ohms)

Range

Accuracy

Resolution

Notes

100

0.1% ± 3 dig.

10m

Max. input 300V DC or AC rms
any range. Max. open circuit voltage 4V

1000

0.08% ± 2 dig.

100m

10k

0.09% ± 2 dig.

1

100k

0.09% ± 2 dig.

10

1000k

0.12% ± 2 dig.

100

10M

0.5% ± 2 dig.

1k

20M

0.5% ± 2 dig.

10k

DC Current

Range

Accuracy

Resolution

Notes

1mA

0.1% ± 3 dig.

0.1µA

Max. input 500mA
Voltage burden <250mV

100mA

0.1% ± 3 dig.

10µA

10A (up to 1A)

0.3% ± 3 dig.

1mA

Max. input 10A
Voltage burden <500mV

10A (up to 5A)

1.0% ± 4 dig.

1mA

10A (up to 10A)

3% ± 10 dig.

1mA

AC Current (True RMS)

Range

Accuracy

Resolution

Notes

1mA

0.35% ± 20 dig.

0.1µA

Max. input 500mA
Voltage burden <250mV

100mA

0.35% ± 20 dig.

10µA

10A (up to 1A)

0.5% ± 20 dig.

1mA

Max. input 10A
Voltage burden <500mV

10A (up to 5A)

1.2% ± 20 dig.

1mA

10A (up to 10A)

3% ± 20 dig.

1mA

Accuracies apply over 45Hz to 10kHz for readings above 1000 counts.
Additional error at crest factor = 3 is typically 0.2%.

Frequency

Range

Accuracy

Resolution

Notes

100Hz

0.01% ± 1 dig.

0.01Hz

Sensitivity better than
30mV (100mV range),
better than 10% of range (other Vac & Iac ranges)

1000Hz

0.1Hz

10kHz

1Hz

100kHz

10Hz

Capacitance

Range

Accuracy

Resolution

Notes

10nF

2% ± 5 dig.

10pF

Scale length 1200 counts

100nF

100pF

1µF

1nF

10µF

10nF

100µF

5% ± 5 dig.

100nF

 

OTHER MEASUREMENT FUNCTIONS
Continuity
Selects 1000Ohm range and sounds audible tone for impedance <10Ohm. Sampling rate 20/sec. Max. input 300V DC or AC rms.
Diode Test
Displays voltages up to 1.2V at a test current of 0.5mA. Max. open circuit voltage 4V. Max. input 300V DC or AC rms.
AC + DC Volts, AC + DC Current
Displays the True RMS value of the ac and dc components of the waveform. Accuracy is equal to the sum of the ac and dc accuracies for the selected range.
DISPLAY
Display Type: High contrast LCD. Main display 4½ digits 17mm high, secondary  5 digits 10mm high.
Scale Length: 4¼ digits (12,000 counts) in most modes.
Annunciators: LCD - annunciators for all ranges, functions and program modes.
Reading Rate: Varies with function, maximum 4/sec.
Overrange: Display flashes 12000 if input too great for range.
Overflow: Displays -Or- if calculated result overflows display.
COMPUTING FUNCTIONS
Null (Relative): Stores current reading and subtracts it from future readings.
Ohms Null: Additional non-volatile function for nulling test lead resistance.
Hold: Reading is frozen.
T-Hold: Reading is frozen when stable.
dB: Displays measurement in dBm relative to 600W or other user-entered impedance.
AC plus DC: The RMS value of the ac plus dc parts of the signal is calculated and displayed.
% Deviation: Displays % deviation from entered reference value.
Ax+b: Linear scaling of results, with offset.
Limits: Reading displayed with HI, LO, or PASS with respect to user-defined high and low limits.
Min/Max: Minimum and maximum reading stored.
Power: Calculates V2/R and displays in Watts with respect to a user-defined impedance.
VA: Calculates and displays Volts x Amps.
Data Logger: Manual or automatic storage of 100 measurements. Storage interval 1s to 9999s, manually from keyboard, or by remote contact closure or interface command.
INTERFACES
RS232: Baud rates 2400, 9600 or 19200. Complies fully with the ARC (Addressable RS232 Chain) interface standard. Address selectable from the front panel.
GPIB (option): The 1705 can be specified with an IEEE-488 interface. This version operates only from AC mains.
POWER REQUIREMENTS
AC Input: 115/230 Volts AC nominal 50/60Hz by internal adjustment; 5VA max.
Batteries: 6 x C cells, disposable or rechargeable.
Battery Life: >150 hours from alkaline disposable cells,
typically 70 hours from rechargeable cells.
GENERAL
Operating Range: +50oC to + 40oC, 20% to 80% RH
Storage Range: -20oC to + 60oC
EMC & Safety: Complies with EN50081-1, EN50082-1 & EN61010-1
Size and Weight: 260(W) x 88(H) x 235(D)mm, excl. handle/feet. 2.0kg.
 Thurlby Thandar Instruments Ltd. operates a policy of continuous development and reserves the right to alter specifications 
 without prior notice.

Thurlby Thandar Instruments Limited
Glebe Road, Huntingdon, Cambridgeshire PE29 7DR
Tel: 01480 412451  Fax: 01480 450409  Web: www.tti.co.uk  Email: sales@tti.co.uk