SIGNAL CONVERTERS / AMPLIFIERS WITH 4÷ 20mA OR 0÷ 10Vdc OUTPUT CONFIGURABLE WITH HD788-TCAL BY PC THROUGH RS232C, Model : HD 978TR3 HD 978TR4, Brand : DeltaOhm
HD978TR3 - HD978TR4
Configurable signal converters/ amplifiers with current and/ or voltage
output HD978TR3 and HD978TR4 are signal converters/ amplifiers that can be configured using mV input. The mV input signal range can be configured from -10mV to + 60mV through a button, by using the HD778-TCAL simulator and the DeltaLog7 software or a gauge with mV output. HD978TR3 has a 4… 20mA current output.
HD978TR4 has a 0… 10Vdc voltage output, with 0… 1Vdc, 0… 5Vdc and 1… 5Vdc outputs available upon request.
A led signals the alarm situations and helps the user during the programming phases. The tool is also protected against polarity inversion.
The input and the output are electrically isolated so as to eliminate the problems caused by the reciprocal influence of the devices originating in the
disturbances caused across the various grounding/ earthing routes.
The tool is housed in a 2 DIN module container ( width 35 mm) with normalized connection for 35 mm omega bars.
The 4… 20mA current output stage of HD978TR3 is a two-wired passive type and
supplies power to the converter through the same current loop.
Technical information @ 25° C and 24Vdc
INPUT HD978TR3 HD978TR4
Measurement range -10mV … + 60mV which can be configured
Default range 0 … 20mV
Input impedance > 1 MOhm
Speed of conversion 2 measurements per second
Precision ± 0.04% F.S.± 20¼ V
Functioning temperature -30 … + 70° C
Storage temperature -40 … + 80° C
Relative humidity 0… 90% RH ( without condensation)
OUTPUT HD978TR3 HD978TR4
Type of output ( note 1)
4...20 mA ( or 20...4 mA)
22 mA, in case of
unconnected input 0 … 10Vdc
( 0… 1Vdc, 0… 5Vdc, 1… 5Vdc
Resolution 4 ¼ A 20¼ V
9...30Vdc for the
4… 20mA current output
15… 30Vdc ( 4mA) for the
0 … 10Vdc current output,
10… 30Vdc ( 4mA) for the
Protection against polarity
Sensitivity to Vcc power
voltage variations 0.4 ¼ A/ V 2¼ A/ V
RLMax = ( Vdc-9) / 0.022
RLMax = 625© with Vcc
= 24 Vdc > 10k©
50Vdc ( checked at 250V)
Turns on during the programming phase if the input is unconnected or outside the programmed scale.
Warm-up time 2 minutes
Thermal shift 0.02% F.S./ ° C