HA243821
Issue 5 Mar 98
Section 4
Page 4 - 11
MODEL 346 INSTALLATION AND OPERATION MANUAL
4.8 CHANNEL CONFIGURATION (Cont.)
4.8.8 INPUT TYPE
C1 Input type
Volts
This page is used to define the type of input which is connected to the channel. The up and down arrows are used
to select Volts, millivolts, Ohms or thermocouple as input type.
For direct connection of thermocouples, ‘Thermocouple’ should be selected both here and in the linearisation
page previously described. For indirect connection, Volts or millivolts as appropriate, should be chosen here,
and the relevant thermocouple type in the ‘linearisation’ page described above.
Input low/high defines the actual electrical input. This must lie within the range of the chosen thermocouple.
4.8.9 RANGES, INPUTS & CHART SPANS
Range, Input and Chart span entries combine to define how the measurement is presented on the Display and/or
Chart.
Range:
This is set to include the highest and lowest values to be measured in the Engineering Units to
be used.
Range Low and High Values must be entered for all inputs. This is true even for direct TCs and
RTDs to permit automatic setting of the recorder internal operating span (gain) for these inputs.
Input:
This selection defines the Type of Input to be measured.
Example:
A transmitter ranged for 0 to 1000 litres per minute produces a 4 to 20 mA signal. This is
converted to 1 to 5 volts at the recorder by a 250 shunt. The recorder Input is: lo = 1.00 V.; hi
= 5.00 V. The recorder Range is: lo = 0 litres per minute hi = 1000 litres per minute
The defined Range is used by the recorder to select one of the hardware ranges shown in table
4.8.9 below:
Table 4.8.9 Ranges, accuracies and spans
In order to measure negative going input signals, it is sometimes necessary to make the re-
corder select a higher than normal internal span (with a larger 20 % negative capability) as
described in the channel range calibration description in section 6 of this manual.
Example:
To measure -1.0 V. to 1.0 V., the recorder must select the -1.0 to 5.0 V. internal span. A -100 to
100 foot range with an input of -1.0 to 1.0 V must be configured as a range of -100 to 500 with an
input of 1.0 to 5.0 V.
- 4.0 to + 20 mV
- 12.0 to + 60 mV
- 16.0 to + 80 mV
- 40 to + 200 mV
- 80.0 to + 400 mV
- 0.34 V to + 1.7 V
- 0.50 to + 2.5 V
- 1.00 to + 5.0V
± 0.02 mV
± 0.06 mV
± 0.08 mV
± 0.20 mV
± 0.40 mV
± 1.7 mV
± 2.5 mV
± 5.0 mV
± 0.04 mV
± 0.12 mV
± 0.16 mV
± 0.40 mV
± 0.80 mV
± 3.4 mV
± 5.0 mV
± 10.0 mV
4 mV
15 mV
20 mV
50 mV
100 mV
425 mV
625 mV
1.25 V
Hardware
Range
Input
accuracy
Pen
accuracy
Minimum
span
