D11-044-1: Rapidox 1100ZR-H-OL-LC O
2
Analyser Instruction Manual
D11-044-1
13
Last printed 08/11/2016 12:10:00
3.
RAW (mV
): This setting is for certain customers who like to monitor the raw
sensor EMF signal. The signal from a sensor goes from approximately -50mV
at 100% O
2
through zero at approx 5% O
2
and to +1000mV at extremely low O
2
levels. So, for example, if the scale is set to 0V (output) = -50mV (sensor
voltage at approximately 100% O
2
) and 10V (output) = 250mV (sensor voltage
at approximately 1ppm O
2
) then 5V would indicate a sensor voltage of 100mV.
The scaling of this example is shown in the following plot, from which other
intermediate values can also be read.
Figure 6: Graph showing the raw sensor mV output mode option for oxygen
The following general formulae can be used to calculate the oxygen sensor raw
voltage (O
2mV
) from the voltage or current outputs when set to the raw sensor
voltage output mode:
Output type
Formula for calculating sensor mV from analogue output signal
0-10V
O
2mV
= V
out
/ 10 * (O
2mVH
- O
2mVL
) + O
2mVL
4-20mA
O
2mV
= (mA
out
– 4) / 16 * (O
2mVH
- O
2mVL
) + O
2mVL
Where:
O
2mVL
= user setting of oxygen mV for 0V or 4mA output
O
2mVH
= user setting of oxygen mV for 10V or 20mA output
V
out
= the measured voltage output in volts
mA
out
= the measured current output in mA
The auxiliary outputs are fixed to the pressure sensor on this model. Note that on
analysers coded “OL” the pressure outputs are limited to 0-10V only.
To modify the oxygen analogue output range scroll down the menu to option 4
“Set Outputs” and press ENT. Use the UP & DOWN arrows to select the output
type either “lin(ppm)”, “log(ppm)” or “raw(mV)” and press ENT. You can now edit
the lower and upper values using the UP & DOWN and RIGHT arrows. Once
"Raw(mV)"
Sensor mV output mode
0
1.25
2.5
3.75
5
6.25
7.5
8.75
10
-50
0
50
100
150
200
250
Raw sensor voltage (mV)
O
2
V
o
lt
s
o
u
tp
u
t
4
6
8
10
12
14
16
18
20
O
2
m
A
o
u
tp
u
t