JSON buffer - wrong data using SparkJson library

Struggling to figure out why the code below is returning incorrect json data for the ORP measurement but a direct publish to Particle cloud is correct. See switch (code), case 1. The resulting json shows the ph measurement for the ORP reading

int channel_ids[] = {98,99};

char *channel_names[] = {"ORP","PH"}; 

StaticJsonBuffer<200> jsonBuffer;

JsonObject& root = jsonBuffer.createObject();

void setup() {                      // startup function
  Serial.begin(9600);	            // Set the hardware serial port.
  Wire.begin();			    // enable I2C port.
  Particle.variable("poolTemp", fahrenheit);
  Particle.publish("version", "v1.2");

void loop() {
  //get and send temp
  if (millis() - msLastSample >= msSAMPLE_INTERVAL){

  if (millis() - msLastMetric >= msMETRIC_PUBLISH){
    Serial.println("Publishing now.");
    root["timestamp"] = Time.now();

    //write json string
    root.printTo(jsonString, sizeof(jsonString));
    //publish the json to particle cloud
    Particle.publish("PoolSensor", jsonString,60,PRIVATE); 

void publishTempData(){
  if(!ds18b20.crcCheck()){      //make sure the value is correct
  sprintf(szInfo, "%2.2f", fahrenheit);
  Particle.publish("Temp", szInfo, PRIVATE);
  Blynk.virtualWrite(V5, szInfo);
  root["temp"] = szInfo;
  msLastMetric = millis();

void getPublishProbes(){
  for (int channel = 0; channel < TOTAL_CIRCUITS; channel++) {       // loop through all the sensors

    Wire.beginTransmission(channel_ids[channel]);     // call the circuit by its ID number.
    Wire.write('r');        		              // request a reading by sending 'r'
    Wire.endTransmission();          	              // end the I2C data transmission.

    delay(1000);  // AS circuits need a 1 second before the reading is ready

    sensor_bytes_received = 0;                        // reset data counter
    memset(sensordata, 0, sizeof(sensordata));        // clear sensordata array;
    Wire.requestFrom(channel_ids[channel], 48, 1);    // call the circuit and request 48 bytes (this is more then we need).
    code = Wire.read();

    while (Wire.available()) {          // are there bytes to receive?
      in_char = Wire.read();            // receive a byte.

      if (in_char == 0) {               // null character indicates end of command
        Wire.endTransmission();         // end the I2C data transmission.
        break;                          // exit the while loop, we're done here
      else {
        sensordata[sensor_bytes_received] = in_char;      // append this byte to the sensor data array.

    Serial.print(channel_names[channel]);   // print channel name

    switch (code) {                  	    // switch case based on what the response code is.
      case 1:                       	    // decimal 1  means the command was successful.
        root[channel_names[channel]] = sensordata; //adds sensor data to the json buffer for given the channel name (ORP, PH)
        root.printTo(jsonString, sizeof(jsonString));
        Particle.publish(channel_names[channel], sensordata);
        Blynk.virtualWrite(channel_ids[channel], sensordata); 
        break;                        	    // exits the switch case.

      case 2:                        	    // decimal 2 means the command has failed.
        Serial.println("command failed");   // print the error
        break;                         	    // exits the switch case.

      case 254:                      	    // decimal 254  means the command has not yet been finished calculating.
        Serial.println("circuit not ready"); // print the error
        break;                         	    // exits the switch case.

      case 255:                      	    // decimal 255 means there is no further data to send.
        Serial.println("no data");          // print the error
        Particle.publish("poolmon2", "No Data");
        break;                         	    // exits the switch case.

  } // for loop