73-5071: HSE Universal Multi Sensor Amplifier Custom Version

73-5078: HSE Universal Multi Sensor Amplifier for HSE Sensors

Introduction

This User's Manual explains the installation, function and use of the HSE Universal Multi Sensor Amplifier. Carefully read the operating instructions as well as other materials in this manual.

This manual is not a warranty of product performance. If you need help or have questions, please contact us and we will assist you. We want you to be completely satisfied with this product.

Product Overview

The HSE Universal Multi Sensor Amplifier is designed for measurement applications in animal experimental research or other technical uses in general laboratory, light industrial or office environments. The amplifier system is based on a resistance full bridge circuit and available ready set and calibrated to one of the HSE sensors or those of other vendors. If using other sensors, there may be different connection cables available. The amplifier is factory calibrated to the sensor if such is ordered together with the amplifier. 

Key Features (all Versions)

• Amplification of sensor signals measuring for example pressure, force or displacement
• Three measurement range settings, these can be used for low, mid and high measurement ranges for one specific sensors. Or you can use three different sensors without the need to change gain settings as long as there are no jumper changes needed.
• Internally pre-set gain for each range, abandoning the possibility of unintended gain change leading to issues comparing repeating measurement. 
• Zero adjustment over full measurement range
• Bright display of measurement values, adjustable contrast
• Analog output +5V for range maximum
• Output voltage adjustment for analog output signals
• Serial output of measurement values via USB port

Detailed Description

Main Design Features: Front

Main Design Features: Rear

Setting up the system

1. Position your amplifier on a solid, flat surface
2. Connect your sensor to the input at the rear of the amplifier, close the union nut
3. Plug in the power cord to the input voltage connector at the rear of your amplifier
4. Connect the power cable to a wall outlet socket
5. If you want to connect the amplifier to a data acquisition, connect the BNC analog output at the rear to the BNC input of your data acquisition system using a BNC cable. 

Changing sensor type

The HSE Universal Multi Sensor Amplifier is prepared to work with all HSE sensors that need to connect to a bridge-amplifier. To adjust the amplifier to the selected sensor you always must enter a specific menu via the buttons and display of the amplifier. For some of the sensors you must in addition open up the amplifier and change jump settings, as these sensors are very different from others by means of amplification factor and other features. 

Please notice that when ordering a sensor together with the amplifier, the amplifier is factory set according to the sensor. There are not adjustments needed in that case. 

The sensor that ONLY need to be selected via the software menu:

• APT300 Pressure sensor
• FT20 force sensor, using low or mid- measurement ranges
• FT50 force sensor 
• K30, 100, 300 and 1000 force sensors
• Millar Single Pressure Sensor

Please note that when changing back to these sensors from one of the below listed you need to make an adjustment of the jumpers as well.

The sensors that need adjusting of the internal jumper:

• P75 pressure sensor
• DLP 2.5 pressure sensor
• MPX pressure sensor
• FT20 force sensor, using all three measurement ranges
• FT300 force sensor
• B40 balance arm sensor

Selecting the sensor type via the menu of the amplifier:

1. To enter the selection menu make sure the amplifier is switched off
2. Press and hold both the "zero" and "range" buttons and then switch on the amplifier. Keep holding the two buttons for a few seconds until the word "sensor select" appears on the display. This takes about 5 seconds.
3. Step through the list of included sensors by pressing "change," if you want to exit the sensor select menu without changing the sensor type, switch off the amplifier.
4. Confirm the selected sensor, press "enter" and the sensor selection will be stored, an according message confirms the change on the display. The actual selected sensor is always displayed during the measurement.

Adjusting the internal jumper settings:

NOTE: To change the jumper setting you must open up the amplifier case.

• Disconnect the amplifier from power
• Open the upper part of the amplifier case by removing the upper 4 screws, upper two on the front, upper two on the rear. Lift the upper part of the case and put aside.
• You find the jumper bank here:

• 

• Change jumper setting according to the following diagram:

• 

• Put back the upper case and reposition and hand tighten the screws, reconnect the power to the amplifier.
• Switch on the amplifier
• Make sure the correct sensor is selected in the menu as well as described above.
• Select the desired measurement range as described below
• If you use the analog output of the signals adjust the voltage as described in section 

Switching on the amplifier

1. Switch on the amplifier pressing the On/Off button on the front
2. The start sequence on the display shows the amplifier and firmware version and the predefined sensor.
3. You can either start your measurement immediately, checking the zero and calibration values, which is always recommended at the start of your daily experiments or in case this is needed to make a change to the measurement range or sensor selected. 

Display

The display at the front shows information about the factory set sensor and current measurement range as well as the actual measurement values and units. To give the best reading comfort, the displayed values are mean values of the actual sensor readings. A mean value over 1000 samples is calculated and the display is updated after 100ms. For fast measurement signals this may lead to deviations of the values displayed and the values transmitted via the analog for serial outputs. Values collected via the analog channel are always raw data. This may not be relevant for slow measurement signals, like blood pressure, where the means are calculated and analog signals correspond well.

The display guides you through the Zero, Calibration and settings processes as well.

Display contrast

The display contrast can be adjusted to different light conditions using a screwdriver turning the trimer that is accessible at the rear of the instrument. please note that always using the maximum contrast leads to earlier ageing of the display and may affect the ability to read the values over time. 

Measurement range

The HSE Universal Multi Sensor Amplifier is equipped with three measurement ranges for optimized performance. Each of these represent a separate gain setting, that can be changed internally by positioning jumpers, according to the sensor selected. Setting these gains internally, makes sure that no unintended change of gain settings, for example on front panel turning knobs, can influence repetitive accuracy of the measurement values.

For example, for the pressure sensor APT300 these are set to provide best precision and dynamics in the ranges 0-50mmHg (low), 0-200mmHg (mid), and 0-400mmHg (high).

Changing the measurement range

To change the measurement range, press the RANGE button on the front for minimum 2 seconds. A beep is heard to confirm that input is valid and then press CHANGE to toggle the ranges and select by pressing ENTER. If you press the RANGE button too short a message will appear on the display.

The menu then proceeds with a two-point calibration. Depending on the sensor and amplifier version installed, a message calls to apply the zero value to the sensor. For a pressure sensor this can be for example 0 mmHg by opening the sensor to atmospheric pressure by turning a stopcock, or 0 mg, or no weight on a force sensor. You can apply every other pressure or force if you want this to become the zero value, but you must be aware, that every measured value below this zero value is shown as a negative value then. When the zero value is applied and stabilized press the ENTER button to confirm, the display proceeds to the second calibration point. 

Depending on the sensor used and range selected, the display calls you to apply a certain pressure, force or unit according to the sensor.

When working with pressure sensors we recommend using either a Manual Pressure Calibrator (HSE part number 73-4479 for the range 0 - 300mmHg) or when high accuracy is desired a KAL 84 Pressure Calibrator as listed: 

• 73-0012: Electronic Pressure Calibrators, Model KAL 84 H, Mercury, Range 1: 0 - 199.9 mmHg, Range 2: 0 - 26.66 kPa, 115VAC, 60 Hz.
• 73-0013: Electronic Pressure Calibrators, Model KAL 84 H, Mercury, Range 1: 0 - 199.9 mmHg, Range 2: 0 - 26.66 kPa, 230VAC, 50 Hz
• 73-0014: Electronic Pressure Calibrators, Model KAL 84 SH, Mercury, Range 1: 0 - 300.0 mmHg, Range 2: 0 - 39.99 kPa, 115VAC, 60 Hz.
• 73-0015: Electronic Pressure Calibrators, Model KAL 84 SH, Mercury, Range 1: 0 - 300.0 mmHg, Range 2: 0 - 39.99 kPa, 230VAC, 50 Hz.

For force measurement we recommend having the appropriate weight at hand. We recommend purchasing the weight at the time you purchase the amplifier/sensor system. Recommended pressure and weight calibration values in Table 2. 

When the appropriate pressure or weight is applied and has stabilized press ENTER. The amplifier stores the value and returns to the main display showing the current applied value. The amplifier and sensor are now ready to start the experiment. 

Set zero measuring values

At least at the start of a daily experimental session the zero value of the amplifier should be checked and if needed reset. To reset the zero value, press the ZERO button on the front panel for minimum 2 seconds. If you press the ZERO button too short, a message will appear on the display. If accepted a sound confirm the selection and the display calls you to apply the zero value to the sensor. For a pressure sensor this can be, for example 0mmHg, by opening the sensor to atmospheric pressure by turning a stopcock, or 0mg, no weight on the force sensor. You can apply every other pressure or force if you want this to become the zero value, but you must be aware, that every measured value below this is shown as a negative value then. When the zero value is applied and stabilized press the ENTER button to conform. The amplifier stores the value and returns to the main display showing the current applied value. The amplifier and sensor are now ready to start the experiment. 

Analog output

The HSE Universal Multi Sensor Amplifier is equipped with an analog output of measuring signals through the BNC connector at the rear of the amplifier. Using a BNC cable to connect to the hardware of the data acquisition package you can further process the data. Please contact your Hugo Sachs Elektronik-Harvard Apparatus sales person for recommendations for data acquisition packages. Output voltage range is +5V. 

The output voltage for the ranges listed in table 1 are factory set to achieve the best results over the entire selected measurement range. Due to potential aging of sensors or external effects (chemicals, heat, moisture etc) or when changing to a new sensor, the resulting output voltage might differ slightly from the factory setting.

The output voltage for a selected measurement range can be adjusted through the trimmers are accessible at the rear of the amplifiers:

H = High range

M = Mid range

L = Low range

to adjust the output voltage connect a voltmeter to the BNC voltage output, read the voltage when applying the calibration value as listed in table 2 and carefully turning the trimmer screw in small steps with a small screwdriver, read the changing from the voltmeter until the voltmeter shows the desired voltage as listed in table 3. Disconnect the voltmeter, the amplifier and sensor are ready to proceed with the experiment.

When you do not use the analog output you do not need to adjust the output voltage.

Serial output of measurement values

The micro-USB port at the rear of the instrument is a serial port that enables reading measurement values with a connected PC, tablet or similar using an appropriate software like HyperTerminal. Please refer to the manual of the device and software you use how to make a connection. The output serial signal of the amplifier is factory set to: 9600 baud rate, no handshake, 8 bits, no RX/TX.

Specifications

Sensor Connection

The HSE sensors are connected to the HSE Universal Multi Sensor Amplifier with a 6-pin socket with screw lock. Sensors that do not have this socket might be connected using adapters or special cables. Please ask application service for further information.