The 851-pH package comprises Windmill Software for Windows, a data logger to measure 12 pH probes and pH signal conditioning.
Price: 1195 GB pounds.

Features

• Monitor 12 pH electrodes or probes, expandable to 16 on request.
• Can also monitor digital inputs, count, control digital outputs and measure temperature, pressure, flow, level, etc
• Read data over an Ethernet network or over the Internet
• Includes the powerful yet easy-to-use Windmill Software for Windows: no programming required
• Automatic ranging lets the software match the pH signal as closely as possible
• Integrating analogue-to-digital converter reduces electrical noise
• Use software to select the resolution of the A-D converter from 12- to 18-bits: choose high resolution for greater accuracy
• Automatic recalibration
• Set two alarms on each pH probe
• Free technical support for life and money-back guarantee if not satisfied

pH Measurement

The 851-pH package comprises an 851 data logger, a pH connection box and Windmilll data acquisition software. Just connect your electrodes to the pH box's input protected sockets, plug the box into the 851 data logger and away you go. This method of connection means you can use the 851 Data Logger to monitor, for example, temperatures, flow or level at the same time as pH

The standard pH package handles 12 pH electrodes, but can be expanded to 16 electrodes on request.

Designed for Accuracy

The voltage produced by a change in pH is very small. A change of one pH unit on the pH scale produces (ideally) a change in voltage of 59.16 mV at 25 ^oC. With the 851-pH package you can choose a narrow input range such as +/- 10 or 100 mV, or select autoranging to let the software automatically choose the best range for your measurements. Choosing the smallest range that encompasses your signals will optimise the resolution of the measurement. You can also choose the resolution of the analogue-to-digital converter, selecting 18-bit for more accurate measurements. The higher resolution slows down the system to 6 samples per second, but as pH changes relatively slowly this is not generally a problem. If you need faster measurements, choose 16- or 15-bit resolution.

An integrating analogue-to-digital converter reduces internal noise and a differential amplifier helps reduce external noise.

To further improve accuracy, make sure you keep the wires between the electrodes and the pH box short - spanning not more than a few meters.

Set Alarms on Each pH Probe

You can set two alarm levels on each pH probe, and specify what happens when an alarm threshold is crossed. For example, an alarm could be sounded or other equipment switched on.

Software

Windmill Software is included in the 851-pH package. This modular suite offers data logging, charting, alarm indication, output control, process mimic generators, sequence control, programming tools and many other modules.

Free Technical Support and Money-Back Guarantee

All our systems come with free technical support for life and a guarantee that if you aren't satisfied we'll give you your money back.

Specifications

 Dimensions (mm)           180 x 120 x 40
 Maximum logging speed     10 scans a second
 Memory                    65000 scans
SOFTWARE
 Operating system          Windows 10, 8, 7 64-bit, 7 32-bit
 Vista, XP, 2000 or 98
ANALOGUE INPUTS
 Maximum # inputs          16 differential
Maximum safe input voltage:
 Power supply on           ±48 V
 Power supply off          ±33 V
 Transient                 ±300 V
Amplifier:
 Ranges (V)                ±0.01, ±0.1, ±1, ±10
 Common mode range         ±13 V
 Relative accuracy of ranges:
 gain = 1000               ±0.1%
 gain = 1, 10, 100         ±0.05%
Analogue to Digital Converter:
 Maximum linearity error   ±0.02%
 Resolution    Integration Time    Samples/Second
 12 bits         2.5 msec          80
 13 bits         5 msec            64
 14 bits        10 msec            48
 15 bits        20 msec            32
 16 bits        40 msec            16
 18 bits       160 msec             6
DIGITAL INPUTS/OUTPUTS
 Maximum # inputs          32
 Maximum # outputs         32
 (selected through Windmill in ports of 8 lines)
 Power-up state            all inputs
 Compatibility             TTL and 5 V CMOS, can be made 
 contact closure compatible
 Range                     0 to 5 V
 Output capability         15 LSTLL loads
 Maximum I/O speed         160 channels per second
COUNTERS
 Maximum # counters        8
 Resolution                23 bits
 Maximum count (events)    1000000
 Maximum frequency         5 kHz
 Minimum pulse width        500 µseconds
 Frequency gate times      1 or 10 seconds
 Compatibility             TTL, 5 V CMOS, can be made
 contact closure compatible
 Input voltage range       0 to 5 V