Micromax SRM100 User Manual

SRM100 Soil pH and Resistivity Meter User Guide

SRM100 Soil pH and Resistivity Meter

User Guide

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Proven compliance solutions.

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Information in this document is subject to change without notice.

© 2017 American Innovations, Ltd. All rights reserved.
American Innovations | www.aiworldwide.com | 12211 Technology Blvd | Austin, TX 78727

Reproduction in any manner whatsoever without the written permission of American Innovations is strictly
forbidden.

The American Innovations logo and icon and MicroMax are trademarks of American Innovations, Ltd.

Other trademarks and trade names may be used in this document to refer to either the entities claiming the
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and trade names other than its own.

June 2017 Part Number 122221-000 Rev. 0

Contents

Chapter 1

Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Controls and Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Contacting Technical Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Chapter 2

Using the SRM100 Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Operations Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Display Readings During Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter 3

Maintenance & Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Probe Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Battery Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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Start Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Idle State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Resistivity State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

pH State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

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Chapter 4

SRM100 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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iii

1

Getting Started

The MicroMax SRM100 Soil pH and Resistivity Meter is a portable, weather-resistant (NEMA 4), hand held
instrument for measuring the pH and resistivity of soil. The soil pH and resistivity measurements are digitally
processed and displayed on the meter’s numeric LCD display. Soil pH measurements are shown in standard pH
units, while resistivity measurements are shown in ohm-cm. The SRM100 Soil pH and Resistivity Meter
incorporates both the measurement of soil pH and soil resistivity from sensors in one convenient and rugged
probe.

For soil resistivity measurements, the SRM100 generates a bipolar square wave at a frequency that is non­harmonic with 60 Hz (97 Hz). This voltage is sensed through a calibrated geometric gap in the tip of the probe
and is then converted directly to ohm-cm units on the display. The soil pH is measured by the chemical reaction
between two elements to provide a voltage proportional to pH. This voltage is conditioned and converted to pH
units on the display.

Overview

• The SRM100 is a single-probe (PIN) soil pH and resistivity meter. The measurements are taken at the

point of the probe’s sensor array.

• The meter’s probe sensors must be in good ground/soil contact to produce the best measurement

results for pH and resistivity. If the probe sensors are placed in rocky, course, dry, or sandy soil, ensure
that the probe sensors are in contact with these soils to achieve accurate measurements.

• The soil pH measurements obtained from the SRM100 are not intended to replace a laboratory prepared

and analyzed soil sample. The soil pH measurement obtained from the meter is an average
measurement at the point where the probe pH sensor has contact with the soil.

• The pH probe sensor creates an electrical chemical reaction between the soil at depth and the two

measurement sensors of the probe. If the soil is not moist at the measurement depth, the pH
measurement may be inaccurate or the pH cannot be measured, which will result in no pH reading being
displayed.

Controls and Display

The SRM100 Soil pH and Resistivity Meter has a two-line LCD display, three control buttons, a battery
compartment, and a probe connector.

1

SRM100 Soil pH and Resistivity Meter User Guide

Figure 1-1. Meter Features

• Display – all readings are shown on a two-line liquid crystal display (LCD). Each line consists of 16

characters. The display is super-twist nematic type for maximum readability and contrast.

• Power – a push button to turn meter on and off. Using normal pressure, hold down for 5 seconds to turn

on and off.

• OHM-CM and pH – push buttons to take either a resistivity measurement (OHM-CM) or a pH

measurement (pH).

• Battery Compartment – the meter uses 4 AA size batteries that are secured in a weather-resistant

compartment on the back of the unit.

• Probe Connector – a twist-lock connector that attaches the meter to the soil probe connecting cable.

Getting Started 2