16

Laboratory Catalogue 2004

1st Edition

16 17

Laboratory Catalogue 2004

1st Edition

17Lab pH-meter,GLP 21

The GLP 21 is the model CRISON recommends. The fact that there are more than 6,000 units on the market speaks for itself.Its memory contains powerful soft-ware which helps the user not only to operate it in classic “functional” mode, but also in “advanced” mode.

Key features

Control over a magnetic or rod stirrer, speed and on/off switch.

Interface for 40-column printer or for computer.

Interface for a PC keyboard, a useful feature for personalising reports.The measurement data appear both on the display and on the printed reports. See examples.

Communications software, optional, which facilitates data transfer and storage on a PC.

Special calibration. Apart from calibration with standard buffers, the GLP 21 can be calibrated using any reference solution.

Password to protect the measurement programme.

Built-in clock, thanks to which the instrument can also be used as a calendar, clock and chronometer.

Display of the time taken for each measurement. The higher this is, the faster the electrode is deteriorating.

Two different modes of operation, one simple and the other advanced, equivalent to two different measurement programs.

In functional mode the GLP 21 operates as a classical pH-meter: - pH measurement, resolution 0.01 pH.- stability reading mode- calibration with two buffers.- transfer of data to a printer or a PC.The user does not have access to modify any of these conditions.

In advanced mode, however, the user can configure his / her own program, selecting:- measurement mode: by stability, continuous and by time.- the units of measurement: pH or mV.- calibrate with 2 or 3 buffers- buffer type, technical or NIST values.- limits to the measurement, making quality control of the samples or process monitoring easier. An acoustic signal warns the user of the existence of abnormal measurements.- define the end point, with a warning once this has occurred.

CertificatesSupplied with the specifications Certificate and the EC Declaration of Conformity as per directive EMC 89/336/EC.For further information, please see page 132

Example of a report from a printer..

Magnetic stirrer recommended

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Laboratory Catalogue 2004

1st Edition

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Laboratory Catalogue 2004

1st Edition

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Display examples

Reading under way during measurement by stability.

Reading completed.

Indications to be followed during calibration.

Details on calibration.

OperationThe GLP 21 software has been designed so that the operator can use this high-performance pH-meter by following on-screen instructions, using a simple keypad and practically without having to read the instructions manual.

Communications software GLP-PCSoftware for windows, making capture and availability of data on PC easier.

PLUG-IN POWER SUPPLY: The instrument is supplied with a 230 VAC plug-in power supply. For 115 VAC, please specify when orderingSENSORS: Electrodes. Please see pages 36... ATC Temperature probe, Please see page 44ACCESSORIES: fl exible arm, electrode cable and 250 ml bottles of pH 4 and pH 7 buffer and electrolyte.OPTIONAL ACCESSORIES: See page 61

PC display examples

Technical specifi cations

Measuring ranges pH -2 ... 16, mV ± 2000, ºC -20 ... 150

Resolution Standard, 0.01 pH, 1 mV, 0.1ºC. Selectable, 0.1 pH.

Measuring error (± 1 digit) ≤ 0.02 pH, ≤ 1 mV, ≤ 0.3 ºC.

Reproducibility (± 1 digit) ± 0.01 pH, ± 1 mV, ± 0.1 ºC.

Input impedance > 1012 Ohm (Ω).

Autom. temperature compensation With Pt 1000 ATC probe. Entering data using the keypad.

pH calibration In 2 or 3 points, validity 0 h…7 days. Special calibration, 1 selectable point between 0…14 pH. Notifi cation of calibration expiry. Option of forced recalibration. Rejection of defective electrodes. Accepted electrode values: - slope 50... 65 mV/pH, at 25 ºC. - sensitivity 86... 110%. - asymmetry potential ± 40 mV.

Autom. buffer recognition Technical (at 25ºC) pH 2.00, 4.01, 7.00, 9.21, 10.90. NIST (at 25ºC) pH 1.679, 4.006, 6.865, 9.180, 10.254.

Measuring programs A fi xed one and a user-modifi able one.

Display Alphanumeric backlit crystal display. 4 lines of 20 characters.

Languages English, spanish, french, italian.

Power up diagnostic RAM, EPROM, EEPROM memories, display and keypad.

Inputs and outputs Measuring electrode, BNC connector. Reference electrode, banana Ø 4. ATC, Pt 1000 type, telephone or banana connector Ø 4. Interface standard PC keyboard. Interface RS 232 C, unidirectional. Polarising current, 10 µA (i.e. for Karl Fischer). Analog outlet, electrode potential follower. Control for CRISON stirrer: On/Off and speed.

Power supply 12 VDC / 275 mA external power supply

Electrical safety Meets EC, EN 61010.

EMC (Electromagnetic compatibility) Meets EC, EN 50081-1 and EN 50082-1.

Permitted ambient conditions Operating temperature 5...40 ºC. Storage and transport temperature -15... 65 ºC. < 80 % relative humidity, non condensing.

Enclosure High density polyurethane and enamelled steel.

Physical parameters Weight 1.580 g, dimensions 180 x 215 x 130 mm.

Specifi cations suject to change without notice

Ordering informationCode Description

21 00 GLP 21 with accessories, without electrode

21 01 GLP 21 with accessories and electrode 52 01, with integrated ATC

21 02 GLP 21 with accessories and electrode 52 02

21 03 GLP 21 with accessories, electrode 52 02 and ATC 55 31

21 04 GLP 21 with accessories, electrode 52 01 and magnetic stirrer

Details on calibration

Reading completed.

Indications to be followed during