SH - intelligent differential pressure transmitter

Basic technical information of pressure transmitter

* pressure difference can be increase to max. common pressure mode level by software
ČSN EN 61326-1

Instructions for use

• Before connection of the transducer into the pressure circuit, it is necessary to verify that the pressure being measured corresponds to the nominal range of this transducer. Even a transient loading over the maximum allowable overpressure may cause a destruction of the measuring membrane!
• If you measure a pressure of aggressive media it is necessary to verify the transducer material compatibility.
• Caution when sealing of thread (with teflon or with oakum) in liquid medium, because of screwing into the closed volume of liquid can cause uncontrollable rise of pressure and destroy this way measuring membranes!
• All S series transmitters are involved in the electrical circuit by the usual manner. Supply volt. is in range 5 to 36V. Especially in 2-wire connection is necessary to have this voltage at the terminals of the sensor, not for supplying whole loop.
• In case that any of screw terminal inputs is empty, it is not possible to connect it somewhere else. Because it is electrically connected with transmitter circuits and wrong connection can result in error, non-functionality or destruction of transmitter. Specification of individual signals is on label.
• All analog and digital circuits of transmitter are galvanically connected to shared ground, node -Ucc. At the combination of analog and digital inputs is necessary to think about it.
• All inputs are separated by 22uH inductors and protected by varistors against short high-voltage spikes.
• Numbering of leads corresponds to numbering of internal screw terminal.
• Pin 6 is connected to the metal box and serves as a shielding around the sensor. Pin is galvanically isolated from electrical circuits of sensor, tested by the 1000V DC.
• For screw terminal is allowed to use only wires with cross section max 1mm2. In case of connection more inputs and outputs we recommend to use wires with smaller cross section.
• During the zeroing phase are disconnected pressure inputs of the transmit ter and pressure inputs of the sensor are connected together. For what small amount of measured media(max. units of mm3) can leak to the other side of diaphragm. Outwards it can look like a negligible leakage, which has no effect on accuracy of the transmitter.

Diagram

Transmitters are connected into electrical circuit by common way. They are protected against supply reversing polarity by series diode. ATTENTION with more-wire connection, when for example changing output and supply wire may cause transmitter damage.
Detailed description all types of electrical connections, pin assignments and protocol description for series communication are in special document, which is a part of transmitter delivery.

Pin assignments

Outputs table, pin assignments of screw terminal and connector

Conector	3	2	1
Screw terminal	1	2	3	4	5	6	7	8	9	10
4 ÷ 20mA	+Ucc	-Ucc				case
0÷20mA	+Ucc	-Ucc	Out			case
0÷10V	+Ucc	-Ucc	Out			case
0÷3V	+Ucc	-Ucc	Out			case
RS232	+Ucc	-Ucc		RxD	TxD	case
RS485	+Ucc	-Ucc		B	A	case
Switching outputs							Re1	Re2	OK1	OK2

Dimensions of pressure transmitter