Download VibWire-101 - Keynes Controls Ltd

9.2
Diagnostics
The menu system of the VibWire-101 enables the device to make an individual measurements upon demand.
An individual measurement can be made
1. Single channel unit
2. Any specified channel on a MUX-16/32 expansion unit
From the main menu select ‘Option 5 - Diagnostics’
Single Channel Operation
When the VibWire-101 operates as a stand-alone device
Option 1 ‘Take Single Reading’
The device scans and reports the sensor values similar to that
shown opposite.
Sensor Results
10.0
Temperature Sensor Configuration
The VibWire-108 uses the in-built thermistor inside a VW sensor
to measure temperature. The menu system enables two
different thermistor sensor details to be predefined and stored
into the instrument.
.The menu system enables both the VW sensor linearisation and
thermistor temperature equations to be configured. The
thermistor resistance and therefore temperature is calculated
using the Steinhart-Hart equation. The output SI unit is in Deg
C.
The VW sensor linearisation uses the industry standard
quadratic equation to convert the VW signal into engineering
units.
Beta Value Thermistor Configuration
Thermistor type 1
1 Type
2 Resistance at T0 (ohms)
3 T0 (Celcuis)
4 Beta
5 Steinhart-Hart 0th order (A)
6 Steinhart-Hart 1st order (B)
7 Steinhart-Hart 2nd order (0)
8 Steinhart-Hart 3rd order (C)
U Up. T Top.
1
3312
22
5234
0.0
0.0
0.0
0.0
Defines the thermistor
calculation type.
The parameters for this part of the instrument configuration can
be found on the VW sensor calibration data sheet.
This parameter takes
priority of any defined
thermistor parameters.
Steinhart-Hart Thermistor Configuration for accurate
readings
The thermistor configuration menu below demonstrates how to
configure the thermistor for use with the Steinhart-Hart
calibration factors.
Appendix C shows a sample VW sensor data sheet and where
the parameters for the Steinhart-Hart 0, 1st, 2nd and third
parameters are found.
The menu above shows the VibWire-101 configured for using
the thermistor Beta value for thermistor temperature value
readings
Note
For lower accuracy temperature readings or when the
calibration factors are not known then the thermistor Beta value,
T0 and R0 parameters can be assigned.
VibWire-101 Vibrating Wire Interface User manual
9