Windmill Software

Data acquisition and control

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751: Multifunction Data Acquisition USB Unit

751 Multi-function USB Data Acquisition with Windmill Software: 16 analogue inputs, 32 digital i/o, 8 counters

For 16 differential analogue inputs, 16 digital inputs/outputs and 8 counters. You can connect eight 751s to one PC. With the addition of suitable Microlink 59x conditioning units, you can also monitor thermocouples, strain gauges, pressure transducers and current. Includes Windmill data acquisition software for logging, charting, output control and direct data transfer to Excel.

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Microlink 840: Versatile Data Logging over Ethernet and Internet

Microlink 840: Versatile data logging

The culmination of 30-years of experience designing data acquisition and control systems has resulted in this extremely versatile, compact unit which lets you monitor analogue transducers, digital sensors, utility meters, machines and digital status. It can also raise alarms and control digital outputs.

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750: Low Cost Measurement & Control

750 USB Data Acquistion with Windmill Software: analogue input, digital i/o, counters, free technical support

16 analogue inputs, 16 digital inputs/outputs, 8 counters and Windmill logging and control software. Connect up to 8 units to a PC. Data saved in text files, or passed directly to Excel.

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pH Data Logging over Ethernet and Internet

851-pH: pH Data Logger with Digital I/O and Counting

This package logs data from 12 pH probes. It comprises Windmill software, a pH data logger and pH signal conditioning. The pH probes connect to BNC sockets. You can read data over an Ethernet network.

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Thermocouple Monitoring

Thermocouple measurement over USB, Windmill 7 software & free technical support

Monitor 16 thermocouples and voltages, digital I/O and counting. Connect 8 units to 1 PC and monitor 128 thermocouples.

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Strain Gauge Monitoring

Strain Measurement:  USB Data Acquisition Unit, Strain Gauge Connection Box, Windmill Software, free technical support

Monitor 16 strain gauges, balanced bridges like pressure transducers or voltage signals. Connect 8 units to 1 PC and monitor 128 strain gauges. Readings in microstrain. Zero reference level can be set in Windmill software. Plus digital input & output and counting.

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Microlink 851-pH: pH Data Logger

DAQ Catalogue | Data Acquisition Hardware: Ethernet and Internet |  Microlink 851-pH: pH Data Logger

851-pH: pH Data Logger with Digital I/O and Counting

851-pH: pH Data Logger with Digital I/O and Counting

Price: 1,255.00 (Excluding VAT at 20%)


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.


  • 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.


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.


 Dimensions (mm)           180 x 120 x 40
Maximum logging speed 10 scans a second
Memory 65000 scans
Operating system Windows 10, 8, 7 64-bit, 7 32-bit
Vista, XP, 2000 or 98
Maximum # inputs 16 differential
Maximum safe input voltage:
Power supply on ±48 V
Power supply off ±33 V
Transient ±300 V
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
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
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

DAQ Catalogue | Data Acquisition Hardware: Ethernet and Internet |  Microlink 851-pH: pH Data Logger