F700

Thermometry Bridge AUTOMATIC SYSTEMS

LABORATORIES

TYPICAL APPLICATIONS

Site Thermometer Calibration

Mass and density

Flow and viscosity

Oceanography

Pump & turbine efficiency

Calorimetry

Thermodynamic research
F700 PRECISION THERMOMETRY BRIDGE
In calibration laboratories, the most important
PC SOFTWARE
consideration is the quality of the fundamental
measurement. ASL's F700 AC bridge technology
represents the peak of performance in its class for You can use U-LOG software for control, data
resistance thermometry measurement and exploits logging and for graphical data presentation of
the inherent advantages of AC bridge technology to measurement data. Optionally you can choose
maintain repeatable measurements of the highest U-CAL software for calibration applications with
precision under practical operating conditions. liquid baths or block calibrators and for generating
calibration certificates

9 10 11 5 1 12 13

8 7 6 5 4 3 2
MAIN FEATURES

Accuracy <±0.5ppm (±0.5mK over full range)

Resolution 0.25ppm (0.25mK over full range)
Like to know more about AC and why AC measurement
Linearity <±1 LSD (±0.25mK over full range) then see the data sheet "Why is AC better than DC ?"

Differential & absolute measurement

Warm up time <30 seconds
Expandable up to 60 channels RESOLUTION

Typical Typical probe Typical

Rs Probe Current range Resolution Remarks

1Ω 0.25Ω 10mA -200°C to +1064°C 1µΩ / 0.001°C Low Ohm SPRT's

A FEW FACTS 10Ω 2.5Ω 5mA -200°C to +1064°C 10µΩ / 0.001°C 962°C limit for ITS-90

10Ω 25Ω 1mA -200°C to +150°C 10µΩ / 0.0001°C Enhanced resolution

The Model F700 is a high
accuracy resistance bridge 25Ω 25Ω 1mA -200°C to +660°C 25µΩ / 0.00025°C SPRT's
designed specifically for use in 100Ω 100Ω 0.5 or 1mA -200°C to +800°C 100µΩ / 0.00025°C Industrial PRT's
resistance thermometry. Its
unique AC bridge circuitry 1000Ω 1000Ω 0.1mA -100°C to +100°C 1µΩ / 0.00025°C Aerospace/averaging PRT's
eliminates thermal EMF effects
to provide you with fast, reliable measurements A TRUE PEDIGREE
under a wide range of real operating conditions. A
special input guard circuit maintains accuracy by National standards laboratories around the world
minimising the effect of probe or cable leakage to require the best instrumentation for their work. The
ground. The effect of cable and probe reactance is majority of these organisations use ASL's top of the
eliminated by an on-board quadrature servo range Models F900 or F18 to set the temperature
allowing you typically to make measurements up to standard in their country, these include 22 out of the
100 metres from the PRT. The differential capability 22 members of the international C.C.T.
allows the resistance of one PRT to be measured (Consultative Committee of Thermometry).
against another directly and provides the most
accurate comparison calibration technique.
 FEATURES

1.525903
Digital display (1) Rt/Rs digital display;0.000 000 to 3.999 999

Auto (2) Selects automatic or manual balance.

Thermometer mA (3) Selectable: 0.1, 0.2, 0.5, 1, 2, 5, 10mA, plus √2 for all values.

Bandwidth Hz (4) Selectable: 0.1, 1 or 10 Hz for the analogue meter.

Check (5) Unity & zero self test confirms accuracy of the 1:1.000 000 ratio & 0.000 000 settings.

Sensitivity (6) Selects gain for manual bridge balance.

Meter (7) Normal: Indicates the balance status of the bridge.

Quadrature: Shows the reactive component of PRT, leads and Rs resistor, if present.
(Automatically cancelled with on board servo).
Residual: Indicates noise and interference from external sources.

Rs trim (8) Allows the internal Rs to be trimmed to precisely 100Ω against an external standard.

Ext/Int Rs (9) Selects either internal 100Ω reference resistor in a temperature controlled oven at 36°C,
or any external reference between 1Ω and 1000Ω.

Lead connections (10) True 4 wire connections for resistance thermometer (Rt) and standard resistor (Rs).

Balance meter (11) Shows bridge balance, quadrature or residual noise, as selected by (7).

LED indicators (12) On-Line: Indicates when F700 is active, or "On-line" with computer.
Oven: illuminates if the internal Rs resistor oven is not at the preset temperature.
Residual: (overload); Indicates very high levels of noise or interference are present.
Quad: Indicates very high levels of quadrature, or reactance, from cables.

Ratio Rt/Rs (13) Rt/Rs decade switches; 7 decades of switches to balance F700 manually.

ACCESSORIES

SB148 10 channel auto/manual multiplexer, with

individual preset "keep warm" current.

SB148/01 As SB148, with 4 individual "keep warm" currents per channel.

SB158 Driver/interface for up to 2 x SB148 or SB148/01 multiplexers (Specify RS232 or IEEE).

SB158/01 Driver/interface for up to 6 x SB148 or SB148/01 multiplexers (Specify RS232 or IEEE).

AS1 System F700 complete with SB148 & SB158 multiplexer in cabinet. (Specify F700A or F700B).

AS2 System As AS1 system, but with SB148/01 multiplexer. (Specify F700A or F700B).

RW1, 10, 25, 100, 1000 "Wilkins" AC/DC standard resistor. Values: 1, 10, 25, 100 and 1000Ω.

RR1, 10, 25, 100 , 1000 Laboratory AC/DC standard resistor. Values: 1, 10, 25, 100 and 1000Ω.

RWTE1,RWTE2 Thermal enclosure for 1 off or 2 off RW & RR resistors.

FR4 Four oven controlled reference resistors in cabinet. Choose 1, 10, 25, 100 or 1000Ω.

F/ACC FA-1, FA-2 and FA-3 cable set.

U-LOG Control and data logging acquisition software. U-CAL software for calibration
applications is an option.
 F700 °C °F
ΩK
mV 0.01 °C
SPECIFICATION
Accuracy F700A: ±1ppm of reading or 1 digit, whichever is the greater.
Equivalent to 0.25mK @ unity ratio (0.01°C) or 1mK over the full range.
F700B: ±0.5ppm of reading or 1 digit, whichever is the greater.
Equivalent to 0.25mK @ unity ratio (0.01°C) or 0.5mK over the full range.
Temperature equivalents for 25.5Ω SPRT against a 25Ω standard @ 1mA.

F700A: ±5ppm @ unity ratio, equivalent to 6mK up to 1064°C.

F700B: ±2.5ppm @ unity ratio, equivalent to 3mK up to 1064°C.
Temperature equivalents for 0.25Ω HTSPRT against a 1Ω standard @ 10mA.

Resolution 1 least significant digit.

Linearity <±1 least significant digit.

Measurement time 10 seconds for full balance.

Warm up time <30 seconds with external standard, <5 minutes with internal standard.

Thermometers R0.01 of 1000Ω, 100Ω, 25Ω, 10Ω, 1Ω or 0.25Ω and any intermediate value.

External standard resistor range 1Ω to 1000Ω AC/DC resistance.

Internal standard resistor 100Ω ±50ppm, with t/c of <0.3ppm/°C, in a temperature controlled oven at 36°C.
A trim control allows calibration against an external standard.

Measurement range 0 - 3.999 999 ratio of two resistors; 0 - 3.999 999Ω where Rs = 1Ω
0 - 399.999 9Ω where Rs = 100Ω; 0 - 1500.000Ω where Rs = 1000Ω

Sensor current 0.1, 0.2, 0.5, 1, 2, 5 or 10mA plus √2 multiplier. Constant current, stabilised to ±1% of
nominal value.

Communications RS232C: 300 baud, 8 bits, no parity and 2 stop bits.

IEEE-488: Address selectable from 0 to 15 (factory default = 9)
Analogue outputs: ±10V null balance signal, unfiltered P.S.D. output.
±10V null balance signal, filtered output (1 Hz bandwidth).

Operating conditions 0°C to 30°C (32°F to 86°F), 10 to 90% RH.

Power requirements 240, 220, 120, 100 VAC (±10%) selectable on rear panel, 50 or 60 Hz, 70VA max.

Dimensions/weight 520mm (W) x 155mm (H) x 466mm (D). 3U x 19" front panel. 15kg.
Standard test conditions: 25.5Ω SPRT @ 0.01°C, 25Ω standard resistor and 1mA sensor current unless otherwise stated.
Specifications are subject to change without prior notice.

AUTOMATIC SYSTEMS LABORATORIES

275 King Henry’s Drive, New Addington,
Croydon, CR0 0AE, UK.

Tel: +44 (0)1689 800799

Fax: +44(0)1689 800405

email: sales@aslltd.co.uk web: www.aslltd.co.uk