2.767.0010 Calibrated Reference A handy instrument, powered by a solar cell, for the easy and rapid checking of titrators, KF instruments, pH meters, conductometers and Rancimats.

Quality assurance in the laboratory





Efficient quality assurance tool The Calibrated Reference gets things straight

It may occasionally happen that an instrument used in the lab appears to be faulty, not functioning correctly, or the measured values displayed untrustwor-thy. In most cases it turns out that there were no faults in the electronic and mechanical parts of the instrument and that the causes were external ones, for example, a problem concerning the electrode or the chemistry involved. The Calibrated Reference allows a quick and easy assessment of the instrument concerned.

A must for the quality-conscious lab The Calibrated Reference is simply con-nected to the measuring instrument to be checked instead of the usual sensor. In this way the functioning and ba-sic accuracy of almost all Metrohm instruments can be easily checked in a The 2.767.0010 in its practical case. The standard cables shown form part of the accessories.

short time. The Calibrated Reference can also be used to check the high im-pedance inputs of instruments such as pH meters or titrators.

The Calibrated Reference offers you the possibility of checking your measuring instrument within the normal operating procedure and therefore within estab-lished methods. This has the advantage that the methods and the selected operational sequences are subjected to a check at the same time.

The 2.767.0010 Calibrated Reference is also ideal for checking particular func-tions of Metrohm instruments using the diagnostic procedures given in the Instructions for use.

Small but sophisticated: a solar cell is the driving force

A solar cell, which can be covered by simply turning a hinged lid, supplies the power for the 2.767.0010 Calibrated Reference. If the lighting conditions are inadequate the output voltage is auto-Checking the pH display of a 744 pH Meter with the Calibrated Reference.

matically switched off.

When the solar cell is active the Calibrated Reference supplies two voltages.

One of them has a value of approximately 1200 mV and is available either directly or via a 1 GΩ resistor. The second voltage is about �340 mV, which corresponds to a pH value of 12.76 (25 °C, slope = 100%, pHas =

7.00).

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2.767.0010 Calibrated Reference



Easy to use

With the solar cell covered the Calibrated Reference supplies resistances of ca. 14.3 kΩ and 460 kΩ.

These can be used for checking current and voltage sources in pH

meters, titrators and KF instruments.

For checking temperature measuring instruments, built-in resistances are used that correspond to the theoretical values for Pt 100 and Pt 1000 temperature sensors at 0 °C.

In this way, the 2.767.0010 Calibrated Reference, together with the two resistances mentioned above, provides a total of four different resistance values, which can also be used to check conductometers.

Highly accurate � even without fine adjustment

With the Calibrated Reference, no fine adjustment is carried out. The tables of values on the front and rear of the hinged lid (corresponding to the open or covered solar cell, respectively) contain the exact values measured on the particular instrument. The resistance values have also been converted into the corresponding conductance (µS) or temperature (°C) values and the voltages into pH values wherever this makes sense. This means that the user can easily compare the display of the measuring instrument being checked directly with the value in the table.

Electrode cable check included In everyday routine work the electrode cables have to meet exacting demands. They are subject to large Certificate of a Calibrated Reference. The tables show the exact values measured on the mechanical forces and also come instrument, above with the solar cell covered, below with the solar cell uncovered.

into frequent contact with chemi-cals. In order to prevent incorrect measurements caused, for example, by deteriorating in-sulation properties, the electrode cables should therefore be included in the testing process. However, this is only possible with sensors fitted with plug-in cables. The original cable is simply unscrewed from the electrode head and attached to the corresponding socket of the Calibrated Reference. If, on the other hand, only the measuring instrument is to be checked, then the tested standard cables included in the accessories of the 2.767.0010 Calibrated Reference should be used. These are also necessary if the sensor does not have a plug-in head but is fitted with a fixed cable.

2.767.0010 Calibrated Reference 3





Technical specifications � scope of delivery Technical specifications

Scope of delivery

Output values of voltage and resistance Solar cell

Solar cell

2.767.0010

Calibrated Reference for mV, pH, W, covered

uncovered

µS, °C

Voltage Resistance

Voltage

including the following accessories: Socket (4): 0 mV

1 GΩ

ca. 1200 mV

2x6.2150.000 Cable plug B � plug B

Socket (5): 0 mV

14.3 kΩ

ca. 1200 mV

1x6.2150.010 Cable 2 x plug B � plug DIN 41524 (for Socket (6): 0 mV*

460 kΩ

ca. �341 mV**

Rancimat, 636 and 670 Titroprocessor) Output values for temperature measuring instruments 1x6.2150.020 Cable plug-in head G � 2 x plug B

Socket (1-2):

100 Ω (Pt 100)

1x6.2150.030 Cable plug-in head G � plug E (DIN

Socket (2-3):

1000 Ω (Pt 1000)

19262)

The values measured on the corresponding Calibrated 1x6.2150.040 Cable plug-in head G � plug F

Reference are printed on the lid. Additional data can be 1x6.2716.020 Carrying case

found on the certificate that accompanies the instrument.

1x8.767.1003 Instructions for use of Calibrated Ref-Ambient temperature

erence

Nominal operating range

5 ... 40 °C

1x8.767.1013 Quick reference leaflet for Calibrated Storage

�20 ... 60 °C

Reference

Transport

�40 ... 60 °C

1x

Certificate for Calibrated Reference Safety specifications

Construction and testing according to IEC publication 1010, safety class 3.

Voltage supply

Solar cell (no batteries)

Dimensions

Width

125 mm

Height

45 mm

Depth

85 mm

Weight

Instrument

ca. 350 g

Instrument including accessories ca. 1 kg

* Corresponds to pH = 7.00 if pHas = 7.00

** Corresponds to pH = 12.76 if pHas = 7.00, slope = 100% and temperature = 25 °C

17672

Subject to modifications

Printed by Metrohm Ltd. Herisau 11-1998

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2.767.0010 Calibrated Reference