Strip Chart Recorders make use of long strip or roll of paper to archive data points over a time period. One or more sensors acquire data. Strip chart makes use of one or more pens to plot data linearly as chart passes through uniform speed. Benefits of strip chart recorders are real-time output, ease of operation and hardcopy produced by the device.
Applications of strip chart recorders are flow rates, pH, pressure, temperature and humidity measurements and other measurement processes as well. The device can be used for recording of continuous processes. Strip chart recorders are available in multichannel or single styles and configurations. Some recorders record information in digital form for downloading it to a computer. The requirement of a strip chart recorder is correct pens and charts.
Strip Chart Recorder Technology
Strip chart recorders give you data. Data is produced by using special sensors attached to the recorder. Sensor types include current, strain gauge or bridge, humidity, pressure, level, pH, pressure and temperature among others.
Sensors can be passive or active devices. Active sensors require power supply for generating a signal. Passive sensors, including thermocouples do not require outside power supply in order to generate the signal. Active device is powered through the recorder and is known as excitation source. The signal excitation can be either through current output or through voltage.
As recorders receive digital signal, sensor input or analog signal chart paper gets driven past the pen or pens at a fast rate by drive mechanism. Pen assemblies use potentiometer or galvanometer to drive marking device.
Galvanometric recorders have light wire coil magnetically suspended which is deflected by sensor current. Pen is used for recording those fluctuations, effectively transcribing sensor current. Sensitivity is limited with galvanometers and analog instruments. Galvanometric recorders have small bandwidth, small response, low sensitivity and low input impedance.
Potentiometric recorders compare input signal with reference that results in error signal that is amplified and drives pen motor. Potentiometric recorders have smaller bandwidth, fast response, high sensitivity and high input impedance.
Gtek are the leading manufacturers of strip chart recorders and offer the device with many features as compared to other devices available in the market.